6 Ancient Mysteries That Archaeologists Still Can't Explain

Some of the most puzzling places in archaeology are not hidden in jungles or buried beneath cities. They sit out in the open, on mountaintops and in farm fields and along riverbanks, and in many cases they have been there for thousands of years. They have been visited, photographed, surveyed and argued over, and yet the basic questions about them remain unanswered. Who built them? Why? And in a few cases, what are they actually hiding? So in this video we will be looking at a series of ancient mysteries scattered across the old world, from a mountain top in Turkey to a Neolithic village in China. And we will be doing so to the extent that we actually can, because for most of these places, the honest answer to the biggest questions is that we do not know. There is a king who raised an artificial mountain peak over what is probably his own tomb and whose tomb nobody has managed to reach. There is a doorway in the Andes that opens onto solid rock. There is a cemetery in Ethiopia full of carved stones that no living person can read. There is a lost Bronze Age culture that came to light only because a river flooded. There is a hillside in India where a god was carved out of stone beneath a sun that seems to have been part of the plan. And there are a few scratches on bone and shell that may or may not be the earliest writing in the world. Some of these places have had decades of serious study, and some have been studied surprisingly little, but all of them have resisted a final answer. So let us begin with that mountaintop in Turkey, because the story behind it is stranger than the statues alone would suggest. Mount Nemrut rises to a little over 2,100 metres in the Taurus range of southeastern Turkey, and for most of history, nobody outside the immediate region seems to have known that anything unusual sat on its summit. It was not until 1881 that a German engineer who was surveying the area came across the site and brought it to the attention of the wider world. What he found up there was essentially an entire sanctuary. There were terraces, enormous statues and a great artificial peak of crushed stone. All of it constructed more than 2,000 years earlier and then simply left to the wind, the snow and the silence of the high mountains. The man responsible was a king named Antiochus I, who ruled a small kingdom called Commagene during the first century BC. Commagene was not a major power by any measure. It was a modest state, caught between the Romans to the west and the Parthians to the east, and it drew its culture from both the Greek world and the Persian world at the same time. Antiochus used that unusual position to his advantage. He claimed descent both from Alexander the Great and from the Persian kings, and the sanctuary he built on Nemrut was designed to celebrate exactly that mixed heritage. Around 62 BC, he had a monument raised on the summit that had little in the way of real parallels in the ancient world. On the eastern and western terraces, Antiochus placed enormous seated statues, each of them somewhere between 8 and 9 metres tall. These were gods, but they were not the gods of any one tradition. Greek and Persian deities were deliberately merged into single figures, so that Zeus was combined with the Persian Ahura Mazda. Apollo with Mithras, and Heracles with Artagnes. And seated among them were statues of Antiochus himself, which effectively placed the king on the same level as the gods, as their equal and their relative. Stone eagles and lions stood along the rows as guardians. In other words, this was a monument built to make a statement. A minor king in a minor kingdom was announcing that he stood at the meeting point of two great civilizations, And that he belonged among the gods of both. And then there are the heads. At some point in the 2000 years since the sanctuary was built, the heads of the colossal statues came off their bodies. Today, they sit on the ground at the base of the seated figures. Huge stone faces resting in the dirt and staring out over the terraces and the valleys below. The effect is, to put it mildly, unsettling. Row after row of calm, serene faces, separated from the bodies they used to crown, scattered across a mountaintop. Exactly how and when this happened is not fully settled. The most likely explanation is earthquakes, since the region is seismically active, and the way the heavy heads toppled fits the pattern of quake damage. But some researchers have wondered whether at least part of the destruction might have been deliberate, an act of iconoclasm carried out by later peoples who had no interest in preserving the images of the old gods. We cannot say for certain, and for now, the heads simply sit where they fell. Still, the strangest feature of Nemrut is not the statues. It is what stands between them. Between the two terraces, there rises a great artificial mound. A peak of crushed rock, roughly 50 meters tall, which was piled up by hand on the summit to make the mountain even higher than nature had left it. This is a tumulus, and it is generally believed to cover the tomb of Antiochus himself. So the king appears to have built his own burial place at the very top of the world that he knew. Underneath a mountain he raised with his own workers, and surrounded by the gods he called his family. And this is where we reach the mystery that has never been solved. The tomb has never been found. Archaeologists are confident that a burial chamber lies somewhere beneath the mound. Reaching it, however, has proven beyond them, and the reason is wonderfully simple. The tumulus is made of loose, fist-sized fragments of crushed rock, and loose material of that kind behaves a bit like a liquid. Every time someone has tried to tunnel into the mound, the same thing has happened. A passage is dug, the surrounding rock slides in to fill the gap, and the tunnel collapses behind the people digging it. The mound protects the tomb simply by refusing to hold a hole. Surveys using scanning techniques have been tried as an alternative to digging, but nobody has yet confirmed exactly where the chamber lies or managed to get inside. If Antiochus is in there, then he has rested undisturbed beneath his mountain of rubble for over two thousand years. There is one more feature at the site which deserves a mention, because it may help to pin down the moment the whole monument was conceived. Among the carvings at Nemrut is a stone relief known as the Lion Horoscope. The arrangement of the stars and planets shown on it appears to correspond to a specific date somewhere around 62 or 61 BC. If that reading is correct, then it may be one of the oldest horoscopes known anywhere in the world. Essentially, a snapshot of the sky on a single day, carved into a mountain to mark either the founding of the sanctuary or some other event that Antiochus considered important enough to preserve in stone. The thing to take from Nemrut is that it was built to be seen. It was a monument placed on the highest ground available so that gods and mortals alike could look at it. Our next mystery is in many ways the opposite. It is a carving in a lonely rock face far from any city, and it is a doorway that leads nowhere at all. High in the Andes of southern Peru, near the shores of Lake Titicaca, and not far from the border with Bolivia, there is a region of red rock outcrops known as Huaymarca. The landscape here is stark and windswept, sitting at more than 3,000 meters above sea level, A place of open sky and weathered stone And cut into one flat face of that rock is a doorway, which has puzzled just about everyone who has stood in front of it. It is called Aramu Muru, and to the local Aymara people, it carries a name that is usually translated as the Gateway of the Gods. The doorway is large, and it is cut with a good deal of precision. The main recess measures roughly seven metres by seven metres, carved back into the flat rock face in the shape of a great door, or perhaps a wide letter T. At the centre of its base there is a smaller niche, about the size of a person, where somebody can stand upright with their back against the stone. From a distance it looks exactly like the entrance to a temple or a tomb, a threshold cut into the cliff that seems to invite you to step through. But when you actually reach it and put your hand into that smaller niche, you meet solid rock. There is no chamber behind it, no passage and no room. The doorway opens onto nothing but more stone. That is the heart of the puzzle. Somebody went to considerable effort to carve a large and deliberate doorway into a cliff, complete with a human-sized niche, and then left it opening onto solid rock. This does not seem to be a failed tunnel, and there is no evidence that a chamber was ever begun behind it. As far as we can tell, the doorway was made exactly the way we find it, which is a threshold with nothing on the other side. The wider world has only become aware of Aramu Muru fairly recently. In 1996, a local mountain guide named José Luis Delgado Mamani drew attention to the site, and he described how he had been led to the great carved doorway. Around the doorway there has since grown up a body of local tradition, and it is that tradition which gives the site its name and its legend. According to the Aymara belief that is attached to it, the doorway is a portal, a threshold used by gods and by great heroes of the past to pass out of this world into another. The most famous story concerns a priest named Aramu Muru, from whom the doorway takes its name. As the tale goes, this priest fled during a time of upheaval, carrying a sacred golden disc, and when he reached the doorway in the rock, he used the disc to open the portal. He then stepped through the solid stone into another world and vanished from this one entirely. Some tellings describe the doorway glowing with a blue light as he crossed over. Needless to say, no hidden chamber and no priest have ever been found. And the story is exactly that, a story. But the doorway itself is real and the questions about it are perfectly genuine. The first of those questions is who carved it and when? The site is often attributed to the Inca, who dominated this region before the Spanish conquest and who were outstanding workers of stone. Yet some people believe the doorway is considerably older, the product of a pre-Inca culture whose traditions were later absorbed into those of the Inca and the Aymara. The honest answer is that it has never been precisely dated, and the carving itself offers very few clues, having been worn by centuries of Andean wind and sun. It also helps to consider the company that the doorway keeps. This corner of the Andes around Lake Titicaca contains some of the most remarkable ancient stonework anywhere in the world. A relatively short distance away lies Tiwanaku, the centre of a powerful pre-Inca civilisation, and near it stands Puma Punku, which is famous for its precisely cut stone blocks, fitted together with an exactness that still astonishes visitors. The people of this region were working stone at a level that very few ancient cultures matched. So a carved doorway in a cliff face, however odd it may be, sits in a landscape where extraordinary stone cutting was clearly within reach. Whoever made Aramumuru had the skill to make it deliberately and to make it precise. So, if it was not a door to another world, what was it for? The mainstream explanation is a good deal more down to earth, although it does not completely close the question. Many researchers think that Aramumuru is a ceremonial carving, possibly never finished, and most likely a kind of false door. False doors are a known feature of several ancient cultures around the world. They are doorways carved into solid stone, or built into walls, that were never intended to be walked through by the living, and which served instead as symbolic thresholds. A point where the world of people met the world of the spirits of the dead. A false door in the Andean tradition, marking a sacred boundary between this world and the next, would fit both the physical form of Aramu Muru and the legends that the Aymara later attached to it. On that reading, the doorway was always meant to lead nowhere, because its purpose was symbolic rather than physical. It was a place where the spirit could cross, even though the body could not. Our next mystery marks something far more concrete than a symbolic boundary. It is a field of carved stones that mark real human graves. And yet the symbols cut into them, and the people who cut them, have been lost so completely that nobody can read what they were trying to say. About 80 kilometers south of Addis Ababa, in the central highlands of Ethiopia, a line of weathered stones rises out of a green field. There are around 36 of them at a site called Tia, tall slabs of grey rock leaning at angles, with their surfaces covered in carved symbols. To someone driving past, they might look like an odd cluster of old markers in the grass. In reality, they are grave markers, and they belong to one of the most enigmatic monuments in all of Africa. A place where we know what lies beneath the stones, but have no idea who put them there or what their carvings mean. Tia is the best-preserved example of a much larger phenomenon. Across this part of central and southern Ethiopia, thousands of standing stones, known as stele, are scattered through the landscape in clusters, the remnants of a widespread tradition of raising carved stones. Over the centuries, many of them have fallen, weathered away, or simply been lost. The group at Tia survived in good enough condition to be studied and protected. And in 1980, it was recognised as a UNESCO World Heritage Site, singled out as the finest surviving example of the Ethiopian stele tradition. The stones themselves are striking when you see them up close. They stand as much as two metres tall, and their flat faces are densely carved. The most common symbol, and the most puzzling, is a shape that looks like a sword, which appears again and again across the stones, sometimes several times on a single slab. Alongside the swords, there are curious geometric marks, shapes that resemble leaves or plants, and a recurring design that some people have compared to a stylised human figure, or even to a number. The carvings were obviously made with care, and they were repeated according to some system that the carvers understood. But the meaning of that system is entirely lost. Nobody today can read what the stones of Tia are saying. What we do know comes from what is underneath them. Excavations at the site confirmed that the stones are grave markers, each raised over the burial of a person or people. The remains found at Tia belonged largely to young adults, and they had been laid in a particular flexed posture, with the body deliberately positioned in the grave. So the stelae were not random monuments at all. They were markers in a cemetery, each carved stone standing over the resting place of someone whom the community had chosen to commemorate with considerable effort. The care taken over both the burials and the carvings points to a society with organized funeral customs and real skill in working stone. One that raised these markers over its dead according to a shared tradition. And this is where the mystery deepens. Because that society has vanished so completely that we cannot even name it. We do not know who carved the stones of Tiya. We do not know what culture they belonged to, what language they spoke, or what they called themselves. There is no surviving oral tradition among the peoples of the region that explains the site, and no written record from any source that tells us who raised the stones or why. The symbols cannot be translated because there is no key to translate them with, there is no related script, and nothing to compare them against. A whole community lived here, buried its dead with ceremony, and marked the graves with a symbolic language, and then disappeared so thoroughly that everything except the stones themselves has been erased. Even the age of the site is uncertain. Most researchers place the Tiya stelae somewhere between the 10th and 15th centuries AD, based on the excavated remains and the limited dating evidence available, although some suspect that the tradition may go back further still. That uncertainty is part of the problem. Without secure dates and without any historical context, the stones float loose in time, connected to no known kingdom or people from the region's recorded past. The swords have attracted particular attention because they may offer a hint about who the buried individuals were. Swords carved on grave markers and appearing so repeatedly and prominently could indicate that the people beneath were warriors. Alternatively, the swords might represent status, achievement, or the manner in which a person lived or died. Some of the stones carry different numbers of swords, which might reflect something specific about the individual in the grave, such as a rank, a count of deeds, or a marker of identity that we can no longer interpret. The young age of many of the people buried there has led to speculation that they died in conflict, although that remains only a possibility. The swords clearly meant something to the people who carved them, but exactly what, we cannot say. It is worth remembering too that Tia represents only a fraction of a much larger tradition, much of which is still largely unexplored. That means the answers about who carved these stones may well be waiting in the fields and hills around it. Our next mystery involves a lost people of a very different kind, an entire ancient civilization that was unknown to history until a river burst its banks and tore the evidence of it straight out of the ground. In the winter of 2001, the Halil River in southeastern Iran flooded. The water rose across the plains of the Jiroft region in Kerman province, and as it surged over the land and then drew back, it stripped away the soil along the banks and exposed something that was not supposed to be there. These were ancient graves, hundreds of them torn open by the flood, with their contents suddenly lying in the open air. Inside them were objects unlike anything that people in the region had seen before. Intricately carved vessels of dark green stone, covered in animals and strange scenes. The remains of a civilisation that history had no record of at all. What happened next was a tragedy for archaeology. Word of the treasures spread quickly, and before any archaeologists had arrived to study the site properly, looters descended on the exposed graves. Local people and organised diggers alike began pulling artefacts out of the ground and selling them, and a stream of ancient objects poured out of Jiroft onto the international black market. Thousands of pieces disappeared into private collections and illicit sales around the world, before the Iranian authorities and archaeologists could step in to protect what remained. Much of what was taken was ripped away from its context, and its exact find spot and its relationship to the graves were lost forever. That is precisely the kind of information archaeologists depend on to understand a site. In effect, a civilization was being emptied out of the earth and scattered around the world before anyone even knew what it was. When archaeologists did arrive and begin proper excavations, which were led by the Iranian archaeologist Yousef Majidzadeh, the scale of what had been uncovered became clear. Jiroft was not a single grave or a minor settlement. It appeared to be the remains of a substantial and sophisticated Bronze Age culture, which had flourished along the Halil River around the 3rd millennium BC, which is roughly the same time as the great civilizations of Mesopotamia and the Indus Valley. And yet, this culture was not in the history books. It had left behind no name that anyone recognized, and it had no known place in the story of the ancient Near East. Majid Zadeh proposed something bold. He argued that Jiroft represented a previously unknown civilization, and he connected it with Aratta, a rich and semi-legendary land mentioned in ancient Sumerian texts as a place of craftsmen and precious materials, which scholars had never been able to locate. Whether Jiroft really is Aratta remains debated, but the suggestion shows just how significant the find was considered to be. Here, potentially, was a lost civilisation rising out of the ground. The artefacts themselves are extraordinary. The most famous are vessels carved from chlorite, a dark, soft green stone that was shaped into bowls, cups, boxes and containers with handles, and then covered in astonishingly detailed carving. Their surfaces show animals of every kind, including scorpions, snakes, eagles, humped bulls and big cats, along with mythological scenes and creatures, human figures and even representations of buildings and architecture. The craftsmanship is fine and confident, the work of skilled artisans following an established artistic tradition. These were not crude objects. They were the products of a culture with wealth, skill, and a rich symbolic world of its own, and one that appears to have traded its distinctive carved stoneware across the ancient world, since similar pieces have turned up at sites It's well beyond Jiroft. Then we come to the most controversial part of the whole story. Among the objects associated with Jiroft, there are a small number that seem to carry inscriptions, marks that some researchers have interpreted as writing. If those marks truly represent a script, and if that script belongs to the Jiroft culture of the third millennium BC, then it could be one of the oldest writing systems ever found, potentially rivaling or even predating the earliest writing of Mesopotamia. That would be a discovery of enormous importance, since it would push the origins of writing into a place and a culture that nobody had previously connected with it. Majid Zadeh and others argued that Jiroft may have had its own independent script, a homegrown system developed by this lost civilization. The claim is genuinely disputed, and for good reason. Other scholars have questioned whether the inscribed objects are authentic products of the Jiroft culture at all, given how much of the material came from looting rather than controlled excavation, which makes it very hard to be sure where any individual object came from. Some have suggested that the inscriptions could be later additions, or simply misread, or that a small number of pieces cannot support such a large claim on their own. So the debate over whether Jiroft had its own ancient writing system has not been settled, and it sits at the centre of the site's mystery. If the script is real and as old as proposed, then it rewrites part of the story of how and where humans first began to write. If it is not, then Jiroft remains a remarkable lost civilisation, but one without the written voice that would let it speak to us directly. The broader significance of Jiroft is hard to overstate. Before the flood of 2001, this corner of southeastern Iran was thought of as peripheral, a region on the edges of the great Bronze Age civilizations, rather than a center in its own right. Jiroft overturned that picture. The evidence points to a sophisticated urban culture with fine craftsmanship, long-distance trade and a complex society, thriving in a place that scholars had overlooked. It suggested that the ancient world was more crowded with advanced cultures than the familiar list of Mesopotamia, Egypt and the Indus had led people to believe, and that others may still be waiting, unrecognised, beneath the ground. In the years since, archaeologists have worked to excavate Jiroft properly and to reconstruct what was lost to the looters. Recovering artefacts, studying the settlements and cemeteries, and trying to piece together the story of a civilisation that was scattered before it could be understood. A great deal has been lost that can never be recovered, with objects sold off without any record, and graves emptied without being studied. In the end, Jiroft was a civilisation dragged into the light by water, and then very nearly lost again to greed. Our next mystery was carved on purpose, deep into the living rock of a hill in India, where an ancient people cut a god into the stone, and seem to have arranged the whole site so that the sun itself would play a part in the story. In the state of Madhya Pradesh, in central India, near the town of Vidisha, a low sandstone hill rises from the surrounding plain. Cut into its rock is a series of cave shrines, carved straight into the living stone more than 1,500 years ago. This is Udayagiri, and it should not be confused with the caves of the same name far to the east in Odisha. The caves in the heart of India are among the most important surviving monuments of one of the country's greatest ancient dynasties, and one of them holds a secret arranged around the movement of the sun. The caves date largely to the Gupta period, roughly the 4th and 5th centuries AD, although some elements may be older. The Gupta Empire is often described as a golden age of ancient India, a time of remarkable achievement in art, science, mathematics and architecture, and Udayagiri was closely tied to Gupta imperial power. Inscriptions at the site are connected to the reign of Chandragupta II, one of the most powerful of the Gupta emperors, and the caves appear to have served not only as religious shrines, but also as a statement of the dynasty's authority, Linking the Emperor to the Gods into the order of the cosmos itself. The most breathtaking feature of Udayagiri is the great relief carved into cave five. It shows the god Vishnu in his form as Varaha, a mighty boar rising up to rescue the earth goddess from the cosmic ocean. In the mythology, the earth had been dragged down beneath the waters and Vishnu took the form of a colossal boar in order to dive down, lift her on his tusk and raise her back into existence. The relief at Udayagiri captures that moment on a monumental scale. The boar-headed god stands powerful and triumphant, the small figure of the earth goddess is held aloft, and rows of gods, sages and celestial beings surround them, all of them witnessing the rescue. It is considered one of the masterpieces of Gupta art, and it is carved with a confidence and grandeur that still stops visitors in their tracks. What makes it even more impressive is that the whole scene was cut directly from the rock of the hillside, shaped out of the living stone rather than assembled from separate pieces. The carvers of Udayagiri cut entire chambers, doorways, pillars and monumental reliefs straight into the hill, working from the outside in and removing exactly the right amount of stone to leave a finished shrine behind. The precision and planning that this demanded. Especially for a scene as complex as the Varaha relief, reflects a mature and sophisticated tradition of rock-cut architecture. But there is another side of the site that has attracted particular fascination in recent years, and that is the possibility that Udayagiri was designed with the sky in mind. The hill sits very close to the Tropic of Cancer, the line marking the northernmost latitude at which the sun appears directly overhead at some point during the year. Researchers studying the site have noted that certain features seem to be aligned to track the sun and to mark key moments in the solar calendar, particularly around the passages and openings of specific caves. The layout of parts of the site and the way that light interacts with it at particular times of year suggests that the builders understood the movements of the sun and deliberately worked them into the design so that the site functioned in part as a marker of the solar year, tied in with the cosmological themes carved into its walls. That adds a remarkable layer of meaning to the place. The Varaha relief tells a story of cosmic order being restored. Of a god raising the world back into its proper position. And the site itself appears to have been arranged in harmony with the actual order of the heavens, the passage of the sun across the sky. Recent scholarship has explored these astronomical and calendrical aspects of the site's design, looking at how the alignments might have worked and what they would have meant to the Gupta builders. What emerges is a monument that combines several purposes at once, namely devotion to Vishnu, a display of imperial Gupta power, and an engagement with the cosmos and the calendar, all woven together into a single site cut from a single hill. So Udayagiri was not simply a set of shrines, it was a carefully constructed statement about the universe and the emperor's place within it. Carved by people who understood both their gods and their sky. The Varaha rising from the cosmic ocean, the alignment with the sun's yearly path, and the imperial inscriptions tying it all to the Gupta throne, together make Udayagiri one of the richest and most layered ancient sites in India, and one whose full meaning scholars are still working to unravel. Our final mystery could hardly be more different. It comes not from a great civilization, but from a small Neolithic village on a Chinese riverbank. And it consists of nothing more than a few simple marks scratched into bone and shell. Marks that may push the history of writing back thousands of years before anyone thought it began. For this last one, we leave behind the kings and empires and travel to a small village on a riverbank in central China, a place called Jiahu in Henan province. There is nothing grand here. With no towering statues, no carved gods, and no monuments cut into stone, what Jiahu holds instead is much smaller, and in its own way, much more startling. A handful of simple marks scratched into tortoise shells and bone thousands of years ago, which may be the oldest writing ever found anywhere. To see why those marks matter so much, it helps to understand how old Jiahu is. The settlement dates to around 6600 BC, which is roughly eight and a half thousand years ago. That places it deep in the Neolithic, at a time when much of humanity was only beginning to settle into farming villages, and Jiahu was a remarkable village. It is one of the most important early Neolithic sites in all of China, and the discoveries made there have reshaped what we thought people were capable of at such an early date. The people of Jiahu were growing rice, making them among the earliest farmers to do so. They were also brewing a fermented drink from rice, honey and fruit, which makes it one of the oldest known alcoholic beverages in the world. And, most famously, they made music. Excavations at Jiahu uncovered flutes carved from the wing bones of cranes and drilled with finger holes, and some of them can still be played today. They are the oldest playable musical instruments ever found. So this was a sophisticated, settled and creative community, existing thousands of years before the rise of the civilisations that we usually think of as the beginning of history. And among everything they left behind are the marks. Cut deliberately into tortoise shells and onto bone and stone, there is a series of distinct symbols. There are not many of them, just a handful of clearly separate signs, but they are unmistakably intentional. These were not accidental scratches or natural cracks. Someone at Jiahu chose to cut these particular shapes into these particular objects, carefully and on purpose. That raises one of the most debated questions in all of archaeology, which is simply, what are they? The possibilities fall along a spectrum. At one end, they could be true writing, symbols that stood for words or sounds, a genuine script that was used to record language. At the other end, they might be symbols with no linguistic meaning at all, such as marks of ownership, decoration, or signs whose significance was understood but which did not represent spoken words. And somewhere in between lies what is usually called proto-writing, a system of meaningful symbols that is on the road toward true writing but is not yet a full script. Where exactly the Jiahu marks fall along that spectrum is the heart of the mystery, and it is genuinely unresolved. What makes the question so charged is the timeline. The earliest writing that scholars widely agree on, which is the cuneiform of Sumer in Mesopotamia and the hieroglyphs of ancient Egypt, appears around 5,000 years ago, in the 4th and 3rd millennia BC. The Jiahu symbols are thousands of years older than that. If they were ever shown to be true writing, they would push the origin of the written word back by a staggering margin. And they would place it not in the Near East, but in China, overturning the accepted story of where and when humans first learned to write. That is an extraordinary claim. And extraordinary claims demand strong evidence, which is exactly why most scholars remain cautious. The careful position held by most researchers is that the Jiahu symbols are deliberate and meaningful but that there is not enough evidence to call them true writing. A handful of signs separated by thousands of years from any developed script cannot on their own prove that a writing system existed. Writing in the full sense requires a set of symbols used consistently to record language and there is simply not enough material from Jiahu to demonstrate that. So the marks sit in an uncertain space, clearly more than random, but not clearly a script, acknowledged as significant while their exact status stays open. There is, however, one detail that makes the Jiahu symbols especially intriguing, and it concerns where some of them were carved. Several of the marks appear on tortoise shells, and those shells were found in contexts that suggest they may have been used in ritual, possibly even in a form of divination. That matters because thousands of years later, in the Bronze Age of China, a well-known practice emerged that used exactly this kind of material. During the Shang Dynasty, around three and a half thousand years ago, diviners inscribed questions onto tortoise shells and ox bones. Applied heat until the shells cracked, and then read the cracks as answers from the ancestors or the gods. The characters they carved onto those shells, known as oracle bone script, are the oldest confirmed form of Chinese writing, and the direct ancestor of the Chinese characters that are still used today. Whether there is any real link between the Jiahu marks and that much later tradition is not something we can say, but the parallel is hard to ignore. What is not in doubt is that the people of Jiahu, eight and a half thousand years ago, were carving symbols that they understood into shell and bone with intention and meaning. Whether or not those symbols count as writing by our strict definition, they represent something profound, which is the human urge to make a mark that stands for an idea, to record something and leave it behind. And that is really the thread that runs through all of these places. A king who wanted to be remembered among the gods. A doorway meant for spirits rather than people. A cemetery of stones whose language has been forgotten. A civilization pulled out of the mud by a flood. A hillside carved to match the sky. And a few scratches on a shell. Each of them was made by people who wanted to leave something behind. And each of them has outlasted the people who made it, as well as the knowledge needed to fully understand it. So here is my question for you. Which of these mysteries do you find the most compelling, and which do you think is most likely to be solved? If you have come across any papers or research on any of these sites, leave a comment with the title or a link, because I would be very interested to read more, and I am sure many of you watching would be as well.