The Forgotten Tunnels Beneath Camden

If you walk through Camden Market on a busy Saturday and look down at the pavement beneath your feet, you will find, set at regular intervals into the road surface, a series of old cast iron grills. They are not drains and they are not decorative. They are ventilation shafts for a tunnel network that has been sealed and abandoned for decades. A labyrinth of Victorian passages running beneath the market stalls, beneath the Regents Canal, beneath the railway lines above. 800 horses once worked down there, hauling railway wagons through near darkness, guided only by the thin bars of daylight falling through those same grills. 27 million people visit Camden Market every year. Almost none of them look down. So what, exactly, is beneath their feet? The answer is one of the most ambitious underground complexes ever constructed in Britain. Flooded engine vaults on a cathedral scale, built by Robert Stevenson in 1837, to haul trains up a mile-long hill on a rope. A labyrinth of horse tunnels stretching for hundreds of metres in total darkness, where 800 animals once spent their working lives without ever seeing the surface. The subterranean remains of a djinn empire that once occupied 20 acres of Camden Town and shipped a whole train's worth of spirits to the London docks every single day. And the site where, on a July afternoon in 1837, information travelled faster than any human being for the first time in history. The story of how it was built, how it was abandoned, and why it might yet be saved, begins with the land itself. Before the railways, before the canal, Camden was countryside. Open fields stretched north from the edge of London towards the hills at Hampstead and Highgate. Farms supplied milk and hay for London's horses. A few scattered dwellings and coaching inns sat along the main road north. The land to the east of what is now Camden High Street belonged to Charles Pratt, the first Earl of Camden. And it is from him that the area takes its name. Pratt had taken his title from Camden Place near Chislehurst in Kent. Itself named after William Camden, the Elizabethan historian who wrote Britannia. The name Camden traces back not to an Earl, but to a scholar who died in 1623. Even the name is borrowed. In 1788, an Act of Parliament authorised Pratt to develop the land. Three years later, in 1791, he let out the ground on leases to build 1,400 houses. To the west, Lord Southampton began his own development in the early 19th century. Within a generation, the open fields had become a suburb. Where cattle had grazed, terraced houses now stood. The countryside was vanishing. What replaced it would be transformed again and again, each time more dramatically than the last. But the first piece of infrastructure to truly transform this landscape was not a road or a row of houses. It was water. The Regent's Canal was the idea of a barge owner named Thomas Homer, championed by the architect John Nash and named after the Prince Regent. The Regent's Canal Act was passed on the 13th of July, 1812, and construction began three months later under the supervision of Nash's assistant, James Morgan. The first section, from Paddington to Camden Town, opened in 1816. The completed waterway, opened in August 1820, ran 8 1⁄2 miles between Paddington and Limehouse, dropping 86 feet through 12 locks. It should have been a triumph. Instead, it was a financial catastrophe, its costs exceeding £870,000, more than twice the original estimate. The canal's own promoter, Thomas Homer, had been convicted of embezzling its funds in 1815, and the canal had been built too close to the start of the railway age to turn a serious profit. At one stage, it narrowly escaped being converted into a railway itself. Barges pulled by horses along the towpath carried timber, coal, ice, and food in and out of London, but they were slow. What was about to arrive at Camden would make the canal look like a relic overnight. In 1830, it was proposed to build a railway connecting London and Birmingham. It would be the first intercity railway authorised to extend into London. The scale was unlike anything that had been attempted before. George Stevenson recommended his son, Robert Stevenson, as chief engineer at a salary of £1,500 per year. Robert Stevenson was 27 years old. In the years ahead, he would become one of the most celebrated engineers in the world, but in 1830, he was simply the son of a famous father given a job of terrifying scale. The 112-mile line took 20,000 men and nearly five years to build. Stevenson took personal responsibility for the first nine miles out of Camden, a section called the Primrose Hill Contract. It proved the most difficult stretch of the entire railway. The problem was the London clay. Blue clay, exposed to the atmosphere, swelled unpredictably, driving the appointed contractor into bankruptcy. His workforce could not cope with ground that moved beneath their feet and pushed against their timber supports. Stevenson personally supervised the replacement workforce, managing hundreds of men, walking the route innumerable times, overseeing every yard of excavation by hand. The Primrose Hill Tunnel, begun in 1834, ran 1,164 yards through the land of Eton College. Eton had held the nearby Chalcox Farm, which gave its name to Chalk Farm as an endowment from Henry VI since the 15th century. The college insisted the trains must not visibly intrude on their estate and that the entrance must be grand. The northern portal, designed in 1837, is built of stock brick and stone with a round arched tunnel mouth and carved lion masks. It was London's first railway tunnel. The spoil dug from the tunnel was not removed. It was dumped locally, raising the ground level by several metres. If the land around Primrose Hill feels higher than it should, that is because it is. But the tunnel was only part of the problem. The gradient between Euston and Camden was extremely steep and an Act of Parliament restricted locomotives from running nearer to London than Camden Town, protecting the wealthy residents from smoke and noise. Stevenson devised a solution. Trains would be hauled up from Euston to Camden by steam-powered winches on a mile-long endless rope, seven inches in circumference, weighing almost 12 tonnes. To house the winding engines, Stevenson constructed a massive underground cavern at Camden. The plan was symmetrical. It measured approximately 170 feet long by 135 feet wide. Two 60-horsepower engines sat in a chamber 100 feet long and 63 feet wide. Boiler rooms flanked the engine chamber with workshops on their south sides. Coal storage vaults ran 116 feet long, 15 feet wide and 20 feet high towards the Regent's Canal. The machines were supplied by Maudslay Sons and Field of Lambeth. On the surface, only two chimneys, each 130 feet tall, marked the presence of this buried cathedral of engineering. Everything else was underground. A passenger arriving at Camden would have seen the chimneys and heard the distant rumble of the engines, but the scale of what lay beneath the surface would have been entirely invisible. The Euston to Boxmoor section opened on 20 July 1837 and this is the part that still does not get the attention it deserves. Five days later, on 25 July, Charles Wheatstone and William Fothergill Cook demonstrated the world's first railway telegraph on the Camden Incline. They had patented one of the first electric telegraphs barely a month earlier, a system using needles on a board that could be moved to point to letters of the alphabet. A four-needle system was installed between Euston Square and Camden Town, a distance of approximately one and a half miles. Robert Stevenson was present alongside Charles Fox, who would later construct the Crystal Palace. When the message came through, Stevenson reportedly cried out in exultation and asked Cook to send his delight back down the line, not once, but twice. At Euston, Wheatstone later wrote that he had never felt such a tumultuous sensation as when, all alone in the still room, he heard the needles click. For the entirety of human history, a message could travel no faster than the person or animal carrying it. On that July afternoon in a tunnel beneath Camden Town, that changed. The age of instantaneous communication began in a railway tunnel in north London, and almost nobody knows it. Despite its success, Stevenson rejected the electric telegraph for signalling on the incline in favour of his pneumatic system, a tube underground through which air was forced to produce a shrill whistle. The railway company told Cook they had no further interest just six weeks later. The winding engines started service on 14 October 1837. From that date, trains of up to 12 coaches weighing about 60 tonnes were worked up the Camden Incline by the Endless Rope, which ran around a 20-foot driving wheel and other large sheaves and pulleys. The through-line from London to Birmingham opened for public service on 17 September 1838. Robert Stevenson's railway was complete. By 1844, he had developed locomotives capable of managing the incline unaided. The rope haulage system became obsolete. Cook and Wheatstone, meanwhile, took their invention to the Great Western Railway, where it famously helped catch the murderer John Towell in 1845. In 1846, the London and Birmingham Railway merged with two other companies to become the London and North Western Railway. The Roundhouse, completed in 1847, was designed by Stevenson and Robert Dockray as a locomotive shed. Dockray had worked under Stevenson from 1835, becoming resident engineer in 1840. The Roundhouse measured 160 feet in diameter, one of the first polygonal engine houses in England. 24 cast-iron Doric columns supported a curved rib framework beneath a low-pitched conical slate roof, topped by a central glazed smoke louvre. A locomotive turntable sat in the centre, and early railway lines radiated outward like the spokes of a wheel, so George Gilbert Scott considered it one of the finest examples of Victorian civil engineering. Within a decade, locomotives had outgrown its turntable. The Roundhouse became a store, then a corn and potato store. That same year, 1847, the obsolete winding equipment was sold, reportedly shipped to a mine in Russia. The underground vaults were sealed and abandoned. They would remain flooded and forgotten for nearly 150 years. In 1879, a second bore was added to the Primrose Hill Tunnel, faithfully replicating Stevenson's original portal design down to the carved lion masks. The eastern portals are now Grade II star-listed buildings. The Camden Goods Depot, which had been established back in 1839 on 30 acres of Lord Southampton's land, had originally stabled 50 horses in the vaults below the sidings. That number did not remain small for long. By 1849, 427 horses were employed on the site. At its peak, around 800 horses worked the marshalling yards at Camden alone. Nationally, the railway company provided accommodation for something like 6,000 horses. At Camden, every railway wagon was pulled into position by a single horse. The scale was industrial, the logistics immense, and the problem was movement. The horses could not cross the railway tracks on the surface. A horse loose on an active line was a catastrophe waiting to happen. The solution was to take them underground. From 1856, a labyrinth of tunnels was constructed beneath the goods depot, running under the Euston mainline, under the bonded warehouses on the canal, and beneath what is now Camden Lock Market. The eastern horse tunnel links stables to the marshalling yards. The western horse tunnel connected the goods depot to stables off Gloucester Road. The route of both can still be traced by those cast-iron grills in the road surface, the ones you might have walked over without a second thought. They were the only source of light for the horses working below. Hundreds of animals, day after day, walking through brick-lined tunnels, pulling wagons loaded with coal and timber and manufactured goods, returning to underground stables to eat and rest and be shod. Their entire working existence took place below street level, and the only natural light they ever saw fell through the ironwork above their heads in thin, pale bars. Horses that were injured were treated in a dedicated horse hospital, built to the northwest of the other stables. They were hoisted from the ceiling in slings to take the weight off their sore legs while they recovered. When they healed, they went back underground. The Camden Railway Heritage Trust describes this complex as the most complete example of Victorian industrial stabling that survives in London, and probably the country, in terms of scale, complexity and quality of surviving structures. The horse hospital is now a music venue and art gallery. It is a Grade II star-listed building. If you are finding this worth your time, subscribe. We cover stories like this every week, and there are centuries of London still waiting to be told. But the horses were not the only empire beneath Camden. Walter and Alfred Gilbey, who had founded their drinks firm upon their return from the Crimean War, signed their first lease at Camden on the 24th of September, 1869, for 21 years. The first buildings they occupied were a shed, south of the canal, and the roundhouse itself, which became a bonded warehouse. A bonded warehouse was where goods liable to excise duty were stored before distribution and sale. Any tax had to be paid before items were removed, which required customs and excise officers to be stationed on the premises permanently. When Gilbeys took over the roundhouse, the railway tracks inside were removed, and a substantial wooden gallery was built to carry vats of maturing whisky and brandy. The building that Sir George Gilbert Scott had admired as one of the finest examples of Victorian civil engineering was now filled with the smell of oak casks and alcohol. The underground vaults, originally designed for coal storage, turned out to be ideal for ageing spirits. The temperature underground was cool, constant, and naturally regulated by the mass of earth and brick above. What Stephenson had built for engines, Gilbeys repurposed for gin. In 1871, they built a distillery on Oval Road. In 1895, they constructed three tunnels under the road to connect it to the basement of their warehouse. The underground network was now carrying gin as well as horses and coal. By 1914, the Gilbey Empire occupied 20 acres of Camden Town, storing 800,000 gallons of spirits and wine. Every day, a whole train left for the London docks to supply markets around the world. It was known as the Gilbey Special. At its peak, Gilbeys was the largest drinks firm in the world, a major employer in Camden for almost a century, operating from premises originally designed to store coal and house the steam engines of Robert Stephenson's rope haulage system. In 1962, Gilbeys merged with United Wine Traders to form International Distillers and Vintners. A decade later, that firm was swallowed by Grand Metropolitan. In 1964, Gilbeys moved its operations to purpose-built facilities in Harlow, Newtown. Almost a century of Camden gin, whiskey and wine was over. The arches fell silent. The vaults emptied. The Gilbey Special stopped running. But the roundhouse had already found a new purpose. From 1966, Stephenson and Dockray's old locomotive shed became a celebrated rock and arts venue. Jimi Hendrix played there. The Doors played there. The last shunting horse on the goods depot was retired the following year, in 1967, ending a tradition of underground horse labour that had lasted more than a century. On 30 March 1974, a small crafts market opened near Camden Lock with 16 stalls, operating every Sunday on an unremarkable site with modest ambitions. But in 1976, when plans for a motorway through the area were abandoned, the market found room to breathe. Within a few years, Camden Market had become a well-known feature of the neighbourhood. It was in that same year, 1976, that the decaying stables and tunnels became the unlikely birthplace of British punk. A disused warehouse in the old Camden Stables, now the Cyber Dog Shop, held a rehearsal space called Rehearsal Rehearsals. One first-hand account from the period describes it as an old customs warehouse with thick, black, damp walls. The Clash formed here, played their first gig here and shot the cover of their 1977 debut album here. The rehearsal space was also the inspiration for the Clash song Garage Land. When they were not rehearsing, the band explored the crumbling tunnels beneath the Victorian warehouses with musicians from the subway sect, pushing through damp passageways that had not seen regular human traffic in decades. It was here that they wrote London's Burning and White Riot. There is something almost too perfect about it. The tunnels that Stevenson built to haul trains on a rope in 1837. The vaults where horses once stood in slings while their legs healed. The arches where Gilby's aged its whiskey for nearly a century. All of it rotting quietly beneath Camden. And into that darkness walked a band whose entire purpose was to tear down the old world and build something angry in its place. Punk Rock, composed in the ruins of Victorian industry. The irony is so clean it barely needs comment. The goods depot itself closed around 1980. The tunnels beneath were sealed or forgotten. The vaults filled with debris and water. The cast iron grills in the road no longer served any purpose. The cobbled yards were rented out to garages and lockups. The great underground spaces sat in darkness. The Roundhouse closed in 1983. During the 1980s and 90s, Camden Market grew into a sprawling complex spread across the very goods yards and stables that the railway company had built a century earlier. The market now hosts 27 million visitors annually. More than Buckingham Palace. More than the Tower of London. But beneath the crowds, the tunnels remained hidden. And it was not until 1993 that the most dramatic piece of the underground puzzle was found again. The stationary winding engine vaults. Stephenson's underground cathedral were rediscovered flooded in 1993. The equipment had been removed in 1847. The vaults had been abandoned for nearly 150 years. For almost a century and a half, they had sat beneath Camden in silence. While above them, the goods yard had worked. Gilbys had bottled gin. The Clash had rehearsed punk rock. And 27 million visitors a year had come to browse the market stalls. Nobody above had any idea what was below. But the brickwork had held and the arches still stood. Peter Darley, founder of the Camden Railway Heritage Trust, has described them as structures on a truly majestic scale of international importance. They are Grade II star-listed buildings. The Roundhouse, which had stood closed since 1983, reopened in 1996 as a centre for the performing arts. A full restoration was carried out between 2004 and 2006 by John McCaslin and partners. Amy Winehouse's last public performance was at the Roundhouse, three days before her death on 23 July 2011. Darley founded the Trust in 2007, following a planning dispute over a canal-side warehouse once used by Jim Henson, creator of The Muppets. The following year, in 2008, the so-called Camden Catacombs, the 1846 vaults under the former construction shop, were stripped out and replaced by 25 retail units for Stables Market. Darley and the Trust have called this a major loss of heritage significance. The refurbishment, they wrote, replaced what had existed before with a solution lacking character or imagination, obliterating all appreciation of what the vaults had previously looked and felt like. The atmospheric Victorian tunnels, with their crumbling brickwork and their sense of deep, undisturbed history, were gone. In their place sat clean, uniform shops, 25 of them lined up in a row. The Catacombs had become a shopping arcade. That same year, on 9 February 2008, a major fire struck Camden Market. The tunnels survived. They always survive. In January 2014, Darley was interviewed by Michael Portillo for the BBC's Great British Railway Journeys, bringing national attention to Camden's hidden underground. The Trust has since commissioned a feasibility study for Stephenson Walk, a pedestrian route linking the Regents Canal with Primrose Hill, providing access to the hidden heritage along the way. The idea is simple. Walk from the canal northward and at every step, encounter the hidden infrastructure that made Camden what it is. From the engine vaults, to the horse tunnels, to the tunnel portals and the stables, all of it opened, all of it accessible, all of it told. The Trust has identified seven wonders of the Chalk Farm railway lands, including the engine vaults, the Primrose Hill tunnel portals, the roundhouse, the stables complex, the horse tunnels, the wine and beer vaults and the interchange warehouse. Four of these hold Grade 2 star designations, a classification given to only approximately 7% of all listed structures in England. Darley's book, Chalk Farm Railway Lands, a guided tour, 1830-2030, published in 2024, ends with a chapter set in the future, envisioning all seven wonders publicly accessible by the year 2030. The tunnels are owned by Network Rail. They are not open to the public owing to the danger of flooding. Access requires special permission and can only be arranged under specific conditions. The bulk of the eastern and western horse tunnels remain intact and uninhabited, but off limits. The wine and beer vaults are the last section of the former catacombs that has not yet been converted to retail. As of 2026, the future of the tunnels remains uncertain, but they are still there. The cast iron grills are still set into the road above. If you stand on one and look down, you can just make out the outline of the passage below, the same passage that once rang with the sound of hooves on brick. The canal still runs past the spot where Gilby's once loaded its barges. The Primrose Hill tunnel still carries trains through the hole that Stevenson carved nearly 200 years ago. The roundhouse still stands, no longer housing locomotives or ageing whisky, but still drawing crowds, still alive. The lion musks still guard the tunnel portals. Darley wrote in 2024 that Camden's railway heritage might be nearly 200 years old, but its story is hopefully far from over. The engine vaults have stood sealed underground since 1847. That is 179 years of darkness. They have outlasted the company that built them, the empire they served, and every version of the city that has risen above them. They are waiting.