This Underwater City Is OLDER Than the Pyramids 🌊🏛️

The ocean covers 71% of the Earth's surface, and most of it has never been seen by human eyes. We have better maps of Mars than we do of our own seafloor. But the real mystery is not hiding in the deep. It's sitting in the shallows. Off the coast of Japan, just five meters down, flat terraces drop in giant steps. Vertical faces. What looks like a ramp, an arch, a deliberate structure the size of a football pitch. Nobody can agree on who built it, or whether anyone did at all. In the North Sea, fishing trawlers have been pulling up mammoth bones, ancient tools, and human remains for over a century, dredged from a drowned landscape the size of Great Britain that was home to thousands of people before the sea took it. Off the coast of India, stone walls and carved anchors sit on the ocean floor, exactly where one of the oldest books ever written says, a great city sank beneath the waves. And in Egypt, colossal statues, ancient ships, and gold coins have been pulled from a harbor floor, where one of the ancient world's greatest ports sat completely hidden for over a thousand years. Here's the thing that connects all of them. At the end of the last ice age, sea levels rose by around 120 meters as the ice sheets melted and every coastline on Earth shifted. Every city, every port, every settlement built on those shores simply went underwater. Most of it is still down there and we are only just starting to find it. So if that sounds like something you want to know more about, sit back, relax, and get comfortable, because we are just getting started. Picture this. You are diving off a small Japanese island in the East China Sea. Visibility is good, and as you descend toward the sea floor, something comes into view that does not look like it belongs there. Flat terraces dropping in giant steps, each one cut clean and level. Vertical rock faces dropping straight down. What appears to be a ramp running along one side. What looks like an arch. A formation covering roughly 150 meters by 40 meters sitting in water between 5 and 27 meters deep. And which looks, from almost every angle, like something that was built. That is what a diver named Kihachiro Arataki found in 1986 off the southern tip of Yonaguni Island, the westernmost island in the Japanese Ryukyu chain, roughly 120 kilometers east of Taiwan. He was not looking for ruins. He was looking for hammerhead sharks, which gather in these waters and attract divers from across the region. What he found instead has been generating serious academic argument ever since. The formation is now known as the Yonaguni Monument, and the reason it matters is not just what it looks like, but when it would have been built if it is man-made. The seafloor where it sits was dry land during the last ice age. If human hands shaped this rock, they did so at a time when Yonaguni was part of a much larger landmass connected to the Asian continent when sea levels were low enough to expose the shelf it now sits on. The last time that rock was above water was somewhere between 6,000 and 10,000 years ago. To put that in context, the oldest confirmed cities in the world, the early settlements of Mesopotamia, date to around 5,500 years ago. If the Yonaguni Monument is artificial and went underwater 10,000 years ago, whoever built it was doing so 4,500 years before we think organized urban civilization began. The most prominent advocate for the artificial interpretation is a Japanese geologist named Masaki Kimura of the University of the Ryukyus. He has been diving and studying the site for decades. What Kimura found when he went through it methodically is a series of features he argues are very hard to account for through natural processes alone. The terraces are not simply stepped. They are consistent in their dimensions across the whole structure in a way that natural erosion rarely produces. The angles between the horizontal surfaces and the vertical faces are close to perfect right angles, and they maintain that consistency across a distance that would be unusual for natural fracturing to replicate so uniformly. Kimura also identified what he interprets as tool marks on several flat surfaces, small parallel scratches consistent with deliberate cutting rather than random weathering. He found what he argues are post holes, circular depressions in the rock that in a construction context would have held wooden structural elements. He documented channels running along the base of some vertical faces that he believes served a drainage function, and he described a triangular depression he interprets as a carved pool or basin. He mapped what he describes as a twin megalith at the western end of the monument, two large upright stone pillars whose positioning relative to the surrounding structure he argues is too specific to be coincidental. Taken together, Kimura describes the overall layout as having a clear internal logic, a main terrace, a surrounding avenue or path, subsidiary structures arranged around it, a deliberate orientation, not a random scattering of naturally eroded features but something with a coherent spatial organization. Whether that organization reflects genuine design or whether the human brain is finding patterns in natural geometry is exactly the question that has kept this debate running for nearly 40 years. To understand why the artificial interpretation has attracted serious attention beyond just Kimura, it helps to know who was actually living in this part of the world at the relevant time. The Ryukyu Islands sit on a chain that once formed a partial land connection between Japan and the Asian continent when sea levels were lower. People have been living in this region for at least 30,000 years, and the Jomon culture of prehistoric Japan is one of the most remarkable and underappreciated chapters in human prehistory. The Jomon produced some of the oldest pottery ever found anywhere on Earth, dating back over 14,000 years, which is several thousand years before pottery appears in the farming civilizations of the Middle East. They built substantial settlements, maintained long-distance trade networks across the Japanese archipelago, and the assumption that people in this part of the world at this date were incapable of large-scale organized construction does not sit comfortably alongside what we actually know about them. The broader region also has a deep tradition of working with stone that tends to get overlooked. The Ryukyu Islands contain ancient stone structures called gusuku, fortified enclosures built from carefully fitted rock, demonstrating that the cultural tradition of stone construction in this specific island chain has genuinely old roots. The confirmed gusuku date to a later period than the Yonaguni Monument would, but they show that this was not a region where stone construction was alien or unfamiliar. Kimura has also pointed out that the orientation of the main terrace at Yonaguni aligns with the position of certain stars at specific times of year, something that has been looked at by researchers interested in ancient astronomy. Whether that alignment is deliberate or coincidental is not something the evidence can currently settle, but it adds another layer to a site that keeps raising questions that have not been cleanly answered. No dateable material or unambiguous artifact has been recovered from the monument that would confirm human modification. But the site has not been comprehensively excavated either. It has been dived and photographed extensively over nearly 40 years, but the sediment around and within the structure has not been systematically examined in a way that could settle the argument. Kimura's specific claims, the tool marks, the post holes, the drainage channels, the twin megalith, have not all been individually addressed and dismissed in the published literature, and the debate between those who see a natural formation and those who see something built by human hands is still very much alive. What Yonaguni does, whatever it eventually turns out to be, is raise a straightforward and genuinely uncomfortable question. If the shallow coastal waters around the world were dry land for tens of thousands of years while people were living on them, what else might be sitting on the seafloor that we simply have not found yet? To see what confirmed ancient underwater ruins actually look like, we need to travel to the Mediterranean, where a complete Bronze Age city is sitting in three meters of water with its streets and buildings still readable from above. From the contested seafloor of Japan we travel to the Mediterranean and to something considerably less ambiguous. Off the southern coast of Greece, near a small village called Elafonisos, the seafloor holds what looks from above like a city seen from a low-flying aircraft, streets running between buildings, courtyards, chamber tombs at the edges of the settlement, a central square, the whole thing sitting in three to four meters of clear shallow water covering roughly 35,000 square meters of submerged urban layout. The site is called Pavlopetri and there is no debate about whether it was built by human hands. It was a city. It sat above the water once. People lived and traded in it across over 2,000 years. And then the sea took it. To understand what kind of world Pavlopetri belonged to, it helps to know something about the Bronze Age Mediterranean. The period between roughly 3000 and 1000 BC was one of the most commercially active eras in the ancient world. Ships were moving across the Aegean, the eastern Mediterranean, and beyond on a scale that would not be seen again for centuries. Copper from Cyprus, tin from as far as Afghanistan and possibly Britain, grain from Egypt, wine and olive oil from the Greek peninsula, luxury goods from across the Near East, all of it moving through a network of ports and trading relationships that connected cultures from the British Isles to Mesopotamia. The Mycenaean Greeks were a major player in this world, running a palace-based economy that collected, stored, and redistributed goods across the region from fortified citadels like Mycenae and Tyrens. Their administrators wrote in a script called Linear B, the earliest known form of written Greek, and the clay tablets they left behind record the meticulous accounting of a civilization deeply invested in trade and production. Pavlopetri sat on a sheltered bay along one of the key sea routes connecting the eastern and western Mediterranean, and it was part of this world for over 2000 years. Ships stopped here. Goods changed hands. People built houses and workshops and tombs and went about their lives in a city that had a defined layout, established streets, and a central public space on a coastline that is now several meters below the water. It was first noticed in 1967 by an oceanographer named Nicholas Fleming, who spotted what appeared to be stone structures on the seafloor while swimming in the bay. A basic survey was done at the time, but the full picture only came together in 2009 when a team from the University of Nottingham, led by archaeologist John Henderson, returned with underwater GPS equipment and high-resolution sonar. What the survey revealed was considerably larger than anyone had expected, with 15 previously unknown buildings identified and the overall scale of the settlement roughly doubled compared to earlier estimates. Pottery analysis and radiocarbon dating placed the city's occupation between approximately 3,200 B.C. and 1,100 B.C., over 2,000 years of continuous use. That puts Pavlopetri squarely in the Bronze Age, the period of Mycenaean Greek civilization that produced the palace culture that Troy and Agamemnon grew out of. The people walking these streets were living at the same time as the cultures whose stories eventually became the Iliad and the Odyssey, and the city they lived in was connected to the same trading networks that moved goods from one end of the ancient world to the other. The finds from the site reflect exactly that. Large numbers of storage vessels consistent with a port handling significant cargo in transit. Spindle whorls showing textile production happening alongside commercial activity. Bronze Age pottery in styles that connect Pavlopetri to the wider Aegean trading network. For 2,000 years, ships stopped here, goods changed hands, and the city functioned as a working part of the ancient Mediterranean economy. Then, around 1,100 B.C., in the same period that the entire Bronze Age palace system across the Mediterranean collapsed in ways that are still not fully understood, Pavlopetri's occupation appears to have ended. The city did not go underwater immediately. That came later, gradually, through a combination of slowly rising sea levels and local land subsidence over the following centuries, until the streets were below the surface and the city was gone. Here is where the story connects to something bigger. The ancient Greeks had a long tradition of stories about land and cities swallowed by the sea, and the most famous, of course, is Atlantis, described by the philosopher Plato around 360 B.C. as a powerful island civilization that sank in a single catastrophic day and night. Mainstream scholarship is clear that Atlantis was philosophical allegory, a story built to make a point about the corruption of power rather than a historical record. That reading is almost certainly correct. But what Pavlopetri shows is that the cultural memory behind stories like Atlantis was not purely invented. Real cities in the Greek world did go underwater. Real coastlines that communities had depended on for generations disappeared beneath the sea. The Greek geographer Strabo, writing in the 1st century B.C., listed multiple settlements along the Aegean and Black Sea coasts that had gone underwater within living or recent memory. He was not writing mythology. He was writing geography. The sea was visibly claiming settlements in the ancient world, and the people who lived through it recorded what they saw and passed it down. That accumulated memory, across generations of coastal communities watching the water rise, fed into a storytelling tradition that reached its most famous expression in Plato's Atlantis. The story resonated because it was drawing on something real, the lived experience of a sea that had been taking land for a very long time. Pavlopetri is one of the clearest physical confirmations of that reality. But what it cannot convey is the full scale of what the sea has taken because it went underwater relatively recently and relatively gradually. The real losses, the coastlines and settlements that disappeared when sea levels rose by 120 meters at the end of the last ice age, were on a scale that makes individual city sites look small. To understand that scale, we need to leave the Mediterranean entirely and travel to a stretch of sea floor between Britain and continental Europe, where something the size of an entire country is sitting on the bottom of the North Sea. For years, fishermen working the North Sea would pull up their nets and find things that had no business being there. Mammoth bones, antler tools, harpoon points carved from bone, occasionally human remains. They came up in trawler nets from the sea floor between Britain and the Netherlands, and for a long time they were treated as curiosities, interesting objects from somewhere deep in the past, with no clear explanation for why they were sitting on the bottom of a busy shipping lane. The explanation, when it came together properly, turned out to be one of the most significant stories in European prehistory. The sea floor between Britain and continental Europe is not empty sand. It is a drowned landscape, a country that used to exist and no longer does. The name Doggerland was coined in 1998 by a researcher named Briony Coles, who produced the first serious attempt at mapping what the landscape would have looked like before the sea took it. The name comes from the Dogger Bank, a shallow sandbank in the middle of the North Sea that represents one of the last parts of Doggerland to go underwater. Coles drew on the accumulated finds from trawler nets, on borehole data from the sea floor, and on the known geology of the region to reconstruct a picture of what was there. What emerged was a landmass connecting Britain to what are now the Netherlands, Denmark, and Germany, stretching across the entire southern North Sea basin, covering an area at its greatest extent roughly the size of Great Britain. And it was not a wasteland. To understand what Doggerland actually was, you have to set aside the idea of the North Sea as it looks today and picture something completely different. Rivers running across a wide flat plain, wetlands teeming with wildlife, forests covering the higher ground, grasslands stretching toward the horizon. It was, by the standards of the time, one of the most productive and resource-rich environments in the whole of Ice Age Europe. Communities of hunter-gatherers lived across it, following herds of mammoth, elk, and aurochs across the seasonal landscape, fishing the rivers, gathering plants in the wetlands, building lives in a place that no longer exists. To understand how it disappeared, you need to understand what happened to the world's oceans at the end of the last Ice Age. Around 20,000 years ago, so much of the planet's water was locked up in the great ice sheets covering much of the Northern Hemisphere that global sea levels were roughly 120 meters lower than they are today. 120 meters is about the height of a 40-story building. Every coastline on Earth was further out to sea than it currently is. Every river delta, every shallow continental shelf, every bay and harbor that exists today was dry land, and people were living on it. As the ice sheets began melting, that water returned to the ocean. Slowly at first, and then faster as the warming accelerated. Over the following 10,000 years, the sea rose across the coastlines of every continent on Earth, pushing inland steadily, swallowing the land that people had been living on for generations. Every settlement built on those coastal plains, every camp, every gathering place, every piece of worked stone and carved bone, went underwater. Most of it is still there. In Northern Europe, Doggerland disappeared in stages as the sea rose around it. The higher ground became islands. The islands shrank. The rivers flooded. And then, around 8,200 years ago, something happened that accelerated the process dramatically. Off the coast of Norway, an enormous section of the underwater continental shelf gave way. The Storrega Slide, as it is now known, was one of the largest submarine landslides in recorded geological history, displacing a volume of sediment roughly the size of Iceland and sending a massive tsunami across the North Sea. The wave would have swept across the low-lying remnants of Doggerland with devastating speed. The communities living on whatever remained of the landscape at that point either reached higher ground, or they did not. The last habitable parts of Doggerland went underwater, and the North Sea closed over them. Here's where this connects to something that stretches well beyond Northern Europe. Researchers, including Bruce Mass of Los Alamos National Laboratory, have spent years arguing that the global pattern of flood myths, stories of a great deluge that destroyed the world and reset human history, found across cultures with no known contact, reflects the real experience of coastal flooding as the Ice Age ended. The Norse had flood myths. The ancient Greeks had flood myths. The Mesopotamians recorded the Epic of Gilgamesh, in which a great flood destroys humanity, and a single man is warned to build a vessel and survive. The Hindu tradition has the story of Manu, warned by a fish of a coming flood, and instructed to build a boat to preserve life. Indigenous communities along the coast of Australia carry oral traditions describing the sea rising and covering their land. Traditions that researchers working with Aboriginal communities and geological data have now confirmed reflect real events going back thousands of years. The common thread across all of these stories, separated by vast distances and by the absence of any known cultural contact, is a world-changing flood that ended what came before. The specific details vary, the hero, the vessel, the divine warning, but the core experience is the same. The sea rose. Everything familiar disappeared. The world had to begin again. In 2009, a major study led by Vincent Gaffney of the University of Bradford produced the most detailed reconstruction of Doggerland yet, using seismic survey data originally collected by oil companies for geological prospecting and reanalyzed to map the ancient river systems and landscape features of the lost land. The study, published as Europe's Lost World, revealed a landscape of extraordinary complexity, with river valleys, estuaries, lakes, and upland areas spread across the North Sea basin. The North Sea Pali Landscapes Project has continued this work since then, and in 2020 researchers announced the identification of what appeared to be a large, ancient freshwater lake bed on the seafloor with sediment cores, suggesting the area around it was occupied by people around 10,000 years ago. Doggerland is the largest single thing the sea took in European prehistory, but the same process was playing out on every coastline on Earth. In Asia, in the Americas, along the coasts of Africa and Australia and the Indian subcontinent, the rising sea was swallowing communities and coastlines and leaving nothing visible above the surface. Some of those losses are only now beginning to be found, and one of the most striking examples sits off the northwest coast of India, where stone structures lie on the ocean floor at exactly the location where one of the oldest books ever written says a great city was taken by the sea. The city is called Dwarka. It sits on the northwestern coast of India, in the state of Gujarat, on the shore of the Gulf of Kambhat, and it is one of the seven sacred cities of Hinduism. Modern Dwarka exists today as a functioning pilgrimage site, visited by hundreds of thousands of people every year. But the Dwarka that matters for this video is the one described in the Mahabharata, one of the great Sanskrit epics and one of the oldest literary works in the world. To understand the Mahabharata's significance, it helps to know what kind of text it is. It is one of the longest literary works ever composed, roughly ten times the length of the Iliad and the Odyssey combined, and it sits at the heart of Hindu religious and cultural tradition in a way that has no direct parallel in Western literature. It was composed and refined over many centuries, with the earliest layers dating back to around the 9th or 8th century BC, and possibly earlier, drawing on oral traditions considerably older than the written text. It is not a simple story. It is an entire cosmological world containing within it histories, philosophies, genealogies, and the Bhagavad Gita, one of the most important texts in Hindu philosophy. Within this vast work, Dwarka appears as a real and specific place, the kingdom built by the god Krishna on an island off the coast of Gujarat. The Mahabharata describes Dwarka as a city of extraordinary beauty, with wide streets, magnificent buildings, and a harbor that handled trade from across the ancient world. After Krishna's death, the text says the sea rose and reclaimed the land on which the city stood, swallowing it in a single day. The description is specific in a way that flood myths rarely are— a named city, a named ruler, a named location, and a precise account of what happened to it. The same Sanskrit tradition contains the Manu flood story, which describes a great deluge covering the entire world. In this version, the sage Manu is warned in advance by a fish that grows progressively larger as Manu cares for it, eventually revealing itself as the god Vishnu in disguise. Vishnu instructs Manu to build a great boat, load it with seeds and animals, and survive the flood that is coming. The structural similarity to the Noah narrative in the Hebrew Bible and the Gilgamesh flood in Mesopotamian tradition is striking, and it is part of the broader pattern that researchers like Bruce Massey have pointed to when arguing that these stories preserve real cultural memories of catastrophic coastal flooding at the end of the Ice Age. The question that underwater archaeology has been trying to answer since the 1980s is whether there is anything on the seafloor off modern Dwarka that corresponds to what the texts describe. The National Institute of Oceanography of India began marine surveys of the area under the archaeologist S. R. Rao, and what they found was genuinely significant. Stone structures on the seafloor, the remains of what appears to be a city grid layout, triangular and rectangular stone anchors of a type used in ancient Indian seafaring, pottery fragments, and a seal-bearing carved animal figures. The depths at which these structures were found are consistent with the sea-level changes that occurred as the Ice Age ended and the waters of the Indian Ocean rose across the coastal shelf. Thermoluminescence dating of pottery samples produced dates ranging from roughly 1500 B.C. back to several thousand years earlier, suggesting occupation across a long period. The stone anchors are particularly interesting because they are of a specific design that changed over time in the archaeological record, and the types found at the Dwarka site are consistent with an earlier period than the city visible above water today. The region around Dwarka was an important part of the ancient Indian Ocean trading world. The Gujarat Coast has been a center of maritime activity for thousands of years, with communities fishing, trading, and sailing across the Arabian Sea to the Persian Gulf, the Red Sea, and the East Coast of Africa. The specific type of stone anchors found at the underwater Dwarka site are connected to this long seafaring tradition, and their presence alongside structural remains points to a working port rather than a ceremonial site. In 2002, the story became considerably more dramatic. The Indian government announced that sonar surveys of the Gulf of Kambat, in deeper water further offshore, had identified what appeared to be the layout of a very large ancient city at depths consistent with much earlier sea levels. Government scientists suggested a possible date of up to 9,000 years ago, which if confirmed, would make it one of the oldest urban sites ever identified anywhere in the world. Here is where it is important to be clear about what has and has not been established. The Gulf of Kambat findings attracted enormous international attention, but peer-reviewed confirmation of the interpretation has not been published. Sonar data of underwater features requires careful interpretation, and natural geological formations can produce patterns that resemble built structures. The artifacts recovered from the area were analyzed by some researchers, but the chain of evidence was not documented to the standard required for mainstream archaeological acceptance. Mainstream archaeology is cautious about the Dwarka claims for straightforward reasons. Identifying underwater structures as a specific named city from an ancient text requires evidence that goes beyond structural remains and pottery fragments alone, particularly when the text is a religious epic rather than a historical chronicle. Whether what lies on the seafloor is the Dwarka of the Mahabharata, an earlier settlement, or some combination of both, the sea off this coast has been keeping something for a very long time. Every site we have looked at so far went underwater gradually. Sea levels rising over centuries, land subsiding slowly, cities finding themselves below the tide line over generations. What comes next is different. This one went under in minutes on a Tuesday morning, and we know the exact time it happened. Port Royal sat on a narrow sand spit extending into Kingston Harbor on the southern coast of Jamaica. In the 1680s, it was one of the most important and most notorious cities in the entire English colonial world. At its peak, it had a population of around 6,000 to 8,000 people, with over 2,000 buildings packed onto a thin strip of reclaimed land that had no business supporting a city of that size. It was the primary base of operations for English privateers and pirates across the Caribbean, a place where enormous amounts of looted Spanish silver changed hands in taverns and counting houses, where merchants and naval officers rubbed shoulders with some of the most dangerous people in the Atlantic world. Contemporary accounts described it as one of the wickedest cities on Earth, a reputation built on decades of sanctioned piracy, open vice, and a complete disregard for the norms that governed life in more respectable colonial settlements. To understand why Port Royal existed at all, it helps to know something about the political situation in the Caribbean in this period. England and Spain were locked in a prolonged struggle for control of the Atlantic trade routes and the wealth flowing from the Americas. The English crown had been issuing letters of marque, official licenses authorizing private ships to attack Spanish vessels and settlements since the reign of Elizabeth I. Port Royal was the base from which this officially sanctioned plunder was organized. Henry Morgan, the most famous privateer of the era, used Port Royal as his home port and launched his raids on Spanish Panama and Portobello from its harbor. When he returned with his plunder, the city celebrated with him. Port Royal was not simply a place where pirates happened to gather. It was a city whose entire economy was built around controlled maritime violence and it was extraordinarily wealthy because of it. On the morning of June 7, 1692, at approximately 1145, a massive earthquake struck Jamaica. What happened next was recorded by multiple eyewitnesses. The ground began to roll like waves, buildings collapsed, and then the sand beneath the city liquefied. The entire waterfront slid into the harbor in minutes. Two-thirds of the city went underwater. A Quaker merchant named John Pike, one of the survivors, wrote an account describing how he watched the ground open and swallow people who had been standing next to him moments before. A naval officer named Captain Crockett wrote that he found himself suddenly swimming in the harbor with the rooftops of buildings visible just below him. A minister named Emanuel Heath recorded that he had been drinking a glass of wormwood wine with the island's president just minutes before the earthquake struck, and that by the time it was over, the president was dead and Heath himself was waist-deep in water in the middle of what had been a street. A tsunami followed the earthquake, sweeping through what remained above water. The combined death toll from the earthquake, the tsunami, and the disease outbreak that followed is estimated at between 2,000 and 5,000 people. Contemporary religious writers had no doubt about what had happened. Port Royal had been destroyed as divine punishment for its wickedness, and the characterization spread quickly through the English-speaking world. It is worth noting that this kind of interpretation, a wicked city brought low by catastrophic flooding or geological disaster, appears across virtually every culture that has ever experienced such an event. The same narrative logic runs through the story of Sodom and Gomorrah, through the Manu flood story, through Plato's Atlantis. The sea takes the wicked. The pattern is so consistent across cultures that it tells us something about how human beings process catastrophic loss. What the sea took at Port Royal was preserved in extraordinary condition. In 1981, archaeologist Donny Hamilton of Texas, A&M University, began systematic excavation of the submerged city, work that continued until 1990. The harbor sediment that swallowed Port Royal created anaerobic conditions, meaning very little oxygen, which stopped the normal process of organic decay almost completely. What Hamilton's team pulled from the seafloor was remarkable. Leather shoes still holding their shape, wooden furniture intact after 300 years underwater, food remains including whole peppercorns and animal bones still in cooking pots. Personal belongings scattered exactly where they fell when the ground gave way. And a pocket watch, its hands stopped at 1143, two minutes before the earthquake struck. Hamilton's excavation also recovered clay pipes, pewter plates, wine bottles still sealed with their corks, navigational instruments, surgical tools, and a remarkable collection of everyday objects that paint a detailed picture of life in a busy 17th century port. Port Royal is the only site in this video where the seafloor functions as a precise historical record. Every other location went under slowly enough that the process of submersion scattered and destroyed much of what was there. Port Royal went under so fast that it was effectively sealed in place. The city is still there, largely intact, sitting on the harbor floor where it landed on June 7th, 1692. What Port Royal makes clear, perhaps more vividly than any other underwater site in the world, is how much information the sea can hold when it takes something quickly enough. Which brings us to the biggest question running underneath this entire video. If a city that went under 300 years ago is this intact, this detailed, this full of recoverable information, what about the cities and coastlines that went under 3,000 years ago or 8,000 years ago or 10,000 years ago? How much is down there? And how much of it will we ever find? Those questions lead us to the Black Sea and to a discovery made by the man who found the Titanic. In 1997, two geologists named William Ryan and Walter Pittman published a book called Noah's Flood. The argument they made was specific and provocative. The Black Sea, they proposed, was not always the saltwater sea it is today. Until around 7,600 years ago, it was a freshwater lake sitting below the level of the Mediterranean and separated from it by a natural land barrier where the Bosphorus Strait now runs. Communities of early farmers had been living on its fertile shores for generations, growing crops and raising animals in what was one of the most productive agricultural environments in the ancient Near East. The communities around the Black Sea in this period were part of a broader flowering of early farming culture across the Near East and Southeastern Europe. The Neolithic agricultural revolution had been spreading outward from its origins in the Fertile Crescent for several thousand years, and the Black Sea shoreline had become home to settled communities with established fields and permanent villages. These were not nomadic hunter-gatherers. They were farmers with permanent homes, stored food, domesticated animals, and a deep connection to specific pieces of land. When the flood came, they had far more to lose than communities that could simply pick up and move. Then the barrier gave way. Mediterranean seawater broke through and flooded the basin, raising the water level rapidly and drowning an enormous area of previously inhabited land. Ryan and Pittman estimated the flooding was catastrophic and rapid, displacing large populations of farmers in every direction into Europe, the Middle East, and Central Asia. They proposed that the cultural memory of this event, carried by those displaced communities as they scattered, is the actual origin of the flood myths that appear across so many cultures. The Noah story, the Gilgamesh flood, the Manu story, all of them, Ryan and Pittman argued, echoing the same real catastrophe from different directions. In 1999 and 2000, Robert Ballard, the oceanographer who located the Titanic in 1985, led surveys of the Black Sea floor to look for evidence of this hypothesis. Using remotely operated vehicles, his team identified ancient shorelines at depths consistent with the pre-flood lake level. And in 2000, at approximately 95 meters depth, they found what appeared to be wooden structures, a collapsed beam, wooden branches and stone tools sitting on what would have been the ancient lake shore. The structures have not been definitively confirmed as human made. What the drilling of the Black Sea floor has confirmed is the transition from fresh water to salt water in the sediment record, broadly consistent with Ryan and Pittman's timeline, though whether the flooding was catastrophic and sudden or gradual over centuries remains debated among researchers. The Atlantis thread comes full circle here. Plato described Atlantis sinking in a single day and night, a timescale that fits a catastrophic flood event far better than the slow post-glacial sea level rise that submerged Pavlopetri or Doggerland. Some researchers have proposed the Black Sea flooding specifically as the historical event behind the Atlantis myth, the memory of a fertile and populous shoreline swallowed by the sea, carrying outward with the displaced survivors and eventually reaching the Greek storytelling tradition that Plato drew on. This remains speculative, but the connection is coherent enough that serious researchers have made it in serious publications. From here we move to the final site in this video, the most confirmed, the most excavated, the most extraordinary in what it has actually produced from the sea floor. A city whose name appears in ancient historical texts, whose location was completely unknown for over a thousand years, and which has been giving up colossal statues, ancient ships, and gold coins every diving season since it was found less than 25 years ago. Everything we have looked at in this video, from the contested terraces off Japan, to the drowned landscape of the North Sea, to the submerged streets of a Bronze Age Greek city, has been building toward a single question. What does it look like when we actually find one of these places properly, when we map it fully and excavate it carefully and pull what it has been keeping from the sea floor? The answer to that question is sitting in Abu Kirbeh, off the northern coast of Egypt, at depths of 4 to 9 meters, and it has been producing extraordinary finds since the year 2000. The city is called Thonis-Heracleion, and it had two names because it had two identities. To the Egyptians it was Thonis. To the Greeks who traded there in enormous numbers from around the 7th century B.C. onward, it was Heracleion. For centuries, these were assumed to be two different cities. Mentioned separately in ancient texts, and believed to sit at different locations along the Egyptian coast. The discovery that they were the same place, confirmed by a single inscribed stone slab pulled from the sea floor, was one of the more satisfying moments in the history of underwater archaeology. To understand what Thonis-Heracleion was, it helps to know something about how Egypt controlled its trade in this period. From around the 7th century B.C. onward, Egypt was deeply integrated into the wider Mediterranean trading world, with Greek merchants in particular playing a major role in the movement of goods in and out of the country. Egypt was an enormously productive agricultural civilization, exporting grain, linen, papyrus, and luxury goods to markets across the Mediterranean, and importing silver, timber, wine, and olive oil in return. The pharaohs were not naive about the value of this trade, and they controlled it carefully. Every ship entering Egypt from the Mediterranean was legally required to pass through a single designated port to pay customs duties before proceeding further into the country. That port was Thonis-Heracleion. For roughly five centuries, from around the 7th to the 3rd century B.C., when Alexandria gradually took over the role, Thonis-Heracleion was the gateway to Egypt. Every merchant ship, every diplomatic vessel, every cargo of grain or silver or luxury goods crossing from the Mediterranean into Egypt passed through its harbor and through the hands of its customs officials. The wealth that flowed through the city was extraordinary, and the temples it supported reflected that wealth. The Great Temple of Amun-Gerab sat at the heart of the city, one of the most important religious sites on the Egyptian coast, drawing pilgrims and offerings from across the Mediterranean world. Herodotus, the Greek historian writing in the 5th century B.C., visited the city and described it as a place of great temples and busy harbors. He recorded the local tradition that Helen of Troy had stopped at Thonis-Heracleion with Paris on the voyage that started the Trojan War, a story ancient enough at the time of his visit that he felt obliged to record it even while questioning its accuracy. After the rise of Alexandria in the 3rd century B.C., the city's importance declined gradually. Then, at some point around the 8th century A.D., it disappeared from the historical record entirely and its location was simply forgotten. The rediscovery came in 2000 when a French underwater archaeologist named Frank Goddio and his team from the European Institute for Underwater Archaeology were conducting a systematic survey of Abu Kirbeh using sub-bottom sonar, a technology that maps the features of the seafloor and the layers of sediment beneath it without any diving required. The sonar revealed the outlines of a city at depths of between 4 and 9 meters spread across a wide area of the bay floor. When the divers went down to look, what they found confirmed what the instruments had suggested and then went considerably beyond it. 16 ancient Greek ships and 64 ancient Egyptian vessels were sitting on the seafloor, some still containing cargo. Colossal statues were lying where they had fallen, including a 5 meter figure of the god Hapi, the deity associated with the flooding of the Nile, recovered intact from the harbor floor after more than a thousand years underwater. Gold coins, bronze weights, jewelry, ritual objects and hundreds of ceramic vessels were recovered across multiple excavation seasons. The remains of the great temple of Amun-Gerab were identified and mapped, giving researchers the first physical evidence of a structure described in ancient texts. The find that confirmed the identification beyond any doubt was a stelae, an inscribed stone slab bearing a decree of the pharaoh Nectanebo I. The text on this stone exactly matched the text on another stelae previously known only from the city of Naukratis, a Greek trading settlement elsewhere on the Egyptian coast. The same decree, issued to both cities simultaneously, had survived in two copies. Finding one on the seafloor of Aboukirbe made the identification of the site as Thaunus Heracleion certain. The reason the city sank connects back to a theme running through this entire video. Thaunus Heracleion was built on the unstable sediment of the Nile Delta, layers of water-saturated sand and silt sitting over more solid ground. The Nile Delta has always been dynamic and unstable, with the river constantly shifting its channels and depositing new material across the flat coastal plain. Building a major city on it was always a long-term risk. A combination of slowly rising sea levels, the weight of the city itself, pressing down on the waterlogged sediment, and regular Nile flooding gradually destabilized the ground beneath it over centuries. A study by Gaudio's team published in 2021 in the journal Quaternary Science Reviews identified evidence of a more dramatic final event. The researchers found evidence of liquefaction, the same process that destroyed Port Royal in 1692, in which saturated ground becomes fluid during seismic activity and loses its ability to support structures above it. This explains one of the most striking features of the Thaunus Heracleion seafloor. The statues and ships are not scattered, as you might expect, from a site that was gradually submerged over a long period. Many of them are where they fell, in positions consistent with the ground giving way rapidly beneath them. The city did not slowly sink. Large sections of it collapsed. The excavation is still ongoing. In 2021, the team announced the discovery of a previously unknown sunken temple and a Greek funerary area containing grave goods of exceptional quality. Material that had been sitting undisturbed on the seafloor for over a thousand years. In 2023, divers recovered a remarkable collection of ritual bronze objects from a buried section of the main temple, sealed in place since the city went under. Gaudio has estimated that only a small fraction of the total site has been investigated so far. Here's the thought that Thaunus Heraklion leaves you with. This was a major city. It was visited by ancient historians. It appeared by name in texts going back thousands of years. And for over a thousand years, nobody knew where it was. It was sitting in four to nine meters of water a few kilometers off the Egyptian coast within easy reach of modern diving equipment. And it took until the year 2000 for someone to find it. The ocean covers 71% of the Earth's surface. The shallow coastal waters where ancient peoples built their ports and their cities are largely unmapped and largely unexamined. We found Thaunus Heraklion. We found Pavlopetri. We are beginning to understand the scale of what Doggerland was. But for every site that has been found, there are dozens that have not been looked for, dozens more that have been looked for without success, and an unknown number sitting in shallow water that we do not even know exist yet.