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Descend Into Great Britain’s Network of Secret Nuclear Bunkers

And meet the determined enthusiast bringing them back to life.

Atlas Obscura

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An annotatable map of the Cold War bunker network, at the regional facility in York. All Photos of York and Castleton by Tessa Bunney.

“It’s a terrible pourer, it spills tea everywhere.” Jack Hanlon is holding up an undistinguished brown teapot. Like everything else in this tiny, windowless room—measuring just 13 feet by 16 feet or so—the teapot is not for appearance or entertaining or even utility, but for basic survival. It would, in theory, be able to provide cups of tea for up to three weeks. Jerry cans of water are lined up along one wall, the cupboard is rammed full of cans, and narrow bunk beds, complete with gray blankets that look as though they were made primarily to be itchy, sit in the corner.

We’re standing in a room buried 10 feet below the North Yorkshire moors in northeast England, near the village of Castleton. The wind howls over the hatch above our heads as Hanlon—no expert, just an enthusiast—describes how the room would have been used, as an outpost of English civility and resourcefulness in the face of a nuclear attack. This bunker is one of hundreds just like it, scattered across the country. They’re no longer in use, having been decommissioned for decades, but they’re a nationwide network of relics of fear—a fear that seems never to have left.

As of September 2018, the “Doomsday Clock,” maintained by the Bulletin of the Atomic Scientists, is just two minutes from midnight—the closest it’s been to nuclear annihilation since the height of Cold War in 1953. If, as UN Secretary-General António Guterres declared in April 2018, “the Cold War is back with a vengeance,” our old monuments to precaution, paranoia, and practicality take on a new, chilling life. We’re not privy to our governments’ current top-secret contingency plans, but these bunkers provide a glimpse of the difficult, high-level decisions and calculated sacrifices that were once made, and how both officials and regular people corralled existential fear with work and routine.


At the Castleton bunker, a metal ladder (left) leads from the blast-proof hatch (top right) to a single, spare room (bottom right).

At 23 years old, Hanlon never knew the Cold War first-hand, but he has always been fascinated with the period, and is perhaps a little wistful that he missed it. The quietly unassuming millennial has worked various jobs, most recently as an undertaker, but he is defined by his hobbies—campanology (the art and practice of bell-ringing) and restoring Cold War bunkers. His gritty determination has earned him the respect of many former military and volunteer officers from the period, some of whom have donated old equipment. Even vandals who took aim at the bunkers have not been an obstacle—he encouraged them to volunteer with the restoration work, and a couple of them are still involved. Today, the fresh coat of khaki green paint on the bunker entrance at Castleton, and the neat post-and-rail fence around the site, just hint at the hard graft, skill, and attention to detail that made this living museum piece.


A VHF radio in the Castleton bunker.

The term “Cold War” is attributed to a 1945 article written by George Orwell to describe a nuclear stalemate between “two or three monstrous super-states, each possessed of a weapon by which millions of people can be wiped out in a few seconds.” Only the United States had the bomb at that point, but Orwell saw where things were going, and by the 1950s his prediction had come to pass. So it was that in 1955, the British Ministry of Defence commissioned a top-secret report (declassified in 2002) to get a sense of what nuclear annihilation might look like. The Strath Report, as it was called, concluded that a Soviet nighttime attack with 10 hydrogen bombs would kill 12 million people (a third of the population at that time) and seriously injure another four million. Food and water would be contaminated, industry shut down, and the National Health Service utterly overwhelmed. There are, in such a case, bad options and worse options, but doing nothing, it was decided, was no option. So the kingdom invested in bunkers.

A network designed to protect as many people as possible was estimated to cost £1.25 billion (equivalent to £30 billion today), and the government decided this was prohibitive. So they prioritized a network of smaller underground facilities that emphasized information, communication, and function after a nuclear attack. Over the next few years, more than 1,500 holes were blasted into the ground, from Cornwall to Shetland, and then a standard concrete bunker was built in each one. These were to be the “eyes and ears” of the country, and the people who manned them tasked with sending data to a network of 29 larger regional headquarters, where they would be collated and used to understand where blasts had occurred, the power of the weapons, and possible fallout patterns. The information could then be shared with military and civilian authorities to help them plan their responses.


The blast and air-proof entrance to the underground headquarters of the Royal Observer Corps (ROC), in Maidstone, Kent, June 1960. Photo from Central Press / Getty Images.

These were not, however, military installations to be manned at all times. Rather, the government recruited a network of 10,000 volunteer civilians, known as the Royal Observer Corps (ROC), which gathered weekly for training at their respective bunkers. During periods of rising tension—such as during the Cuban Missile Crisis in 1962—volunteers were expected to drop their lives, leave their families, and head to the bunkers, where they would be organized into three-person shifts. If a nuclear strike occurred, the entrance hatch would be sealed and it would more or less stay that way for three weeks. “We knew that psychologically this job would be immensely difficult, particularly in the full knowledge of what our families were likely to be facing, just a few miles away,” says Tim Kitching, who served as an ROC officer during the 1980s.

The network was activated in the late 1950s and was in continuous use until 1991, when nuclear tensions eased. The bunkers, which were built on both public and private land, were released into the wild. Today the majority has been demolished, or simply left to flood and rot. But two of these bunkers—Castleton and another nearby called Chop Gate—escaped this fate, thanks to one Jack Hanlon.


Aerial view of the exterior of Castleton bunker in North Yorkshire.

The village of Castleton nestles into an alcove in one of England’s bleakest and most remote regions. Above the village an icy wind rips across the landscape, tearing over sturdy heather shrubs and sending the native red grouse scurrying for cover. This is where, just 20 miles from Fylingdales—a key military target and one of the 30 or so radar stations tasked with watching the skies and providing the country with a four-minute warning of impending missile attack—12 dedicated ROC volunteers trained and met, and where they would have gone had the worst come to pass.

After driving a half-mile up the steep hill out of Castleton, Hanlon pulls over where the moorland plateau begins. In steep glacial valleys off each side of the plateau are marginal pastures enclosed by traditional dry-stone walls. Hanlon and I stomp up a short grassy track to find the timeless view interrupted by something distinctly modern. A small hummocky enclosure emerges from the heather, with a couple of small, angular concrete structures in the middle. A black metal tube like a submarine periscope sprouts incongruously from the ground.


Jack Hanlon, the local enthusiast who restored the Castleton bunker.

“I first came across this when I was 14,” Hanlon explains. “The hatch had been ripped off and the interior was flooded. I realized it was too big a project for me to tackle at that time, but it stuck in my mind.” Some years later he also came across the neighboring Chop Gate bunker and met the owner of the land it was on, a former ROC officer who used to work at it. With the officer’s blessing, Hanlon started to restore Chop Gate. Soon after, he returned to Castleton and boldly approached the landowner—it is on the Danby Estate, owned by Richard Henry Dawnay, the 12th Viscount Downe—for permission. His work at Chop Gate convinced the viscount that Hanlon was up to the task.

Hanlon undoes three padlocks and heaves open the blast-proof hatch to reveal a dark hole, roughly two feet square. A ladder leads into the gloom. We climb gingerly down and step off 15 feet below the surface. Claustrophobia sets in quickly, with only a small square of daylight above, but Hanlon’s presence is oddly reassuring. He feels official—clean-shaven and dressed in heavy work boots, a high-vis waterproof jacket, and warm wooly hat—and exudes an unruffled air of capable competence.


Hanlon’s restored Castleton bunker includes (clockwise from top left) a timing device on light switch, emergency rations and an anemometer for measuring wind, forms to document radiation levels, and jerry cans full of water. The supplies were supposed to last up to three weeks.

My flashlight reveals a tiny vestibule off the entrance shaft containing a chemical toilet. To my left is a darkened doorway. Hanlon flicks on a light, casting the room in a dim orange glow. There’s a ticking noise. The lights are on a timer to conserve precious battery power.

Fixing the lights was one of the first jobs Hanlon tackled when he started work on the Castleton bunker in earnest in April 2017. “We had to remove 300 liters of water first, using a bucket and a pulley,” he says. With a team of practical and handy friends, Hanlon prioritized electricity and used fans on full-throttle to get the place dry. He is not the boasting type, but the before-and-after pictures are remarkable, and the wide range of skills and knowledge required to bring this place back to its original state and function is evident. Former ROC officers—many of whom have advised Hanlon on details and shared old photos, documents, and inventory lists—delight in visiting for a trip down memory lane.

Along the long wall to the left of the entrance are two canvas chairs neatly tucked under a plain wooden table. A small mirror is propped on a shelf above—a rare concession to vanity. On the table, neat piles of forms lie ready for the documentation of weather observations, radiation levels, and whatever other details the volunteers could glean about the location of the blast. At the far end of the room, the metal-framed bunk beds take up the entire width. A map showing the network of bunkers across the country and charts to aid cloud identification line one wall.


Maps and charts on the wall of the Castleton bunker showing the regional network of linked bunkers.

Many of the pieces of period equipment have been donated by ex-ROC officers and are testaments to the power of social media. Hanlon’s Facebook page for the bunker has more than 450 followers, and he has another for Chop Gate with 400 as well. Meanwhile, more than 600 showed an interest in his first open day, when the public was invited to visit. “We had to take bookings as there was no way we could manage 600 people in one day!” he says. Discussions on the page have inspired locals to get involved, and resulted in generous donations of both equipment and specialist knowledge.

Some bunkers were sited in towns or cities, but Hanlon’s are rather remote. Here, the ROC volunteers were most likely to have been called to duty via phone or radio bulletin. If attack was thought to be imminent, one of their first jobs upon arrival would have been to alert the local population with a hand-cranked siren, just like the ones used during air raids in World War II. The other two volunteers would prep the “Ground Zero Indicator”—an instrument that sat above ground. The device used the same principle as a pinhole camera, only it had four holes, one corresponding to each compass point. The bomb blast would sear an image onto light-sensitive paper, and the location and size of the resulting marks could indicate its height and direction. “The big problem,” says Hanlon, “was that one of the volunteers had to go outside after the blast, potentially exposing themselves to the radiation, to collect the paper.”

But this vital information was worth the risk, and the volunteers were expected to communicate it to the regional headquarters at first opportunity. A regional headquarters could then plot a number of ground-zero measurements to determine the power of the weapon, where it detonated, and whether it was an air or ground burst (ground bursts produce far more residual radiation from their fallout).

Claustrophobia sets in quickly, with only a small square of daylight above.

The other essential instrument they operated was the “Bomb Power Indicator,” which consisted of a pipe that connected the surface with the interior of the shelter. Inside, a small set of bellows was attached to the end, which would expand as air rushed in from the blast. The bellows moved a needle, which would indicate the pressure produced by the blast wave—another critical piece of information.

The three observers would then be expected to settle into a pattern of regular readings. Exterior radiation levels could be measured safely from inside, using a “Fixed Survey Meter,” a small console on the desk connected to a detector above, but further meteorological measurements required more trips outside, to record the wind speed, direction, and cloud type.

The original Fixed Survey Meter from the Castleton bunker disappeared long ago, but Hanlon went to enormous lengths to find a replacement. “I heard about a Fixed Survey Meter in a flooded bunker on a remote Scottish island, so I traveled up there, pumped the bunker out, and went down to retrieve it,” he says. He traveled up and down the country and scoured eBay to find period-correct equipment, and took care to renovate and repair what he found using the same materials and equipment as would have been used when the bunkers were in service. “I’ve always been interested in history and I’m a determined kind of person,” he says, with characteristic understatement. “When I first came across photos of these bunkers online I just knew I had to go and find out more.”


Everything, from shaving to measurements to communicating with regional headquarters, would have happened at this desk.

Thanks to Hanlon’s efforts, it is now possible to imagine how it might have felt to live down here, isolated and afraid, while a nuclear war may or may not have been raging overhead. Deep in the cupboard is a small tin of Tommy’s Cooking Fuel, solid fuel that could be used to heat up the contents of a mess tin. Such a moment of gathering to eat baked beans and share a pot of tea would have served as a vital focal point for the bunker inhabitants, a way of creating a routine and distinguishing the hours in the absence of normal day-night cycles.

Despite having somewhat better shelter than most of the general population, the inhabitants of these bunkers knew that their chances of survival would be still relatively slim. As the howling draft coming down the ventilation shaft into the Castleton bunker demonstrates, the protection the bunkers could offer was modest at best. Furthermore, the volunteers were expected to leave for measurements, so long-term safety was clearly not a goal. Despite feeling confined, I am reassured by the organization and purpose I see around me. Even if it didn’t offer the greatest protection, I can imagine that useful activity would feel superior than merely awaiting my fate.

Over a steaming coffee in the city of York, former ROC officer Tim Kitching explains the government’s Cold War strategy to me. “The risk of losing observers [due to radiation exposure] was outweighed by the gain in information from the Ground Zero Indicator readings,” he says. Certainly the bunkers were intended to aid survival, and support the continuance of some form of governance after a nuclear exchange, but their primary role was as a passive deterrent. “This warning and monitoring system was designed to support our own forces in surviving a first strike in sufficient numbers to strike back, thereby deterring any aggressor in making first use, knowing that there was a degree of certainty that they would be hit back,” he says.


A tray for forms at the Castleton bunker.

Kitching, who is smartly turned out in creased slacks, and has an organized and efficient air about him, was motivated to serve in the ROC out of a desire to contribute to the defense of the country. “Being ready to do what we were training to do was simply part of the country’s insurance policy,” he says. Kitching was confident that the system would have worked well. “Within the Corps there was multiple ‘redundancy’ built in throughout,” he explains. “So, for example, posts had a complement of 10, but only three were needed for an operational crew.” The overall simplicity enabled them to live off the grid—without piped-in gas, electricity, or water.

There was, however, one link—a weak link—between the bunker and the rest of the world, its overground telephone connection, which was used to transmit information between monitoring posts and to the regional headquarters. The wooden poles and looping wires that connected bunkers in the early days of the network would almost certainly have been knocked over by a nuclear blast, which would have left the bunkers isolated and the precious observations completely useless. By the 1980s, the British Government lessened this risk by investing in private, underground telephone wires between bunkers. Furthermore, monitoring posts were grouped into clusters of three or four, each about 15 miles apart and linked by telephone. One bunker in each cluster served as a “master post,” equipped with radio communications to back up the telephone system. Castleton was one of the lucky bunkers, and held a radio and antenna.

In the Castleton bunker, Hanlon points out the bright yellow “Tele-Talk” loudspeaker telephone on the desk, and the prized VHF radio set on a small shelf above. With luck, Castleton would have been able to communicate its observations, and hopefully those of the other bunkers in its cluster (Hinderwell and Goathland, in this case), to the regional headquarters, 50 miles away in the historic city of Durham.


The York Cold War Bunker, hidden inside a grassy hill, was surrounded by an orchard when it was built. Today it is on a suburban cul-de-sac.

The Durham regional headquarters no longer exists, so instead I travel south to York to see the only one of the 29 regional headquarters to have been preserved. The York Cold War Bunker is one of the city’s best kept secrets, situated out in the suburbs, on a nondescript street, lined with ordinary houses and neatly mowed lawns. At the end of a cul-de-sac, however, is a distinctly extraordinary sight. A rectangular grassy mound rears up to around 10 feet above street level. A flight of concrete steps leads up the mound to a flat-roofed, boxy green building. Locals call it the “Aztec Temple.”

When it was in use, this building was hidden in a hollow, surrounded by an orchard, hundreds of yards from a main road. Since 2006, English Heritage has operated it as an unusual tourist attraction. The visible structure is just the top level of a three-story building hidden in the hill. The lower two levels are further covered in three layers of asphalt, and then at least three feet of earth—all to protect against a blast, heat, and radiation.


The Lower Operations Room at the York bunker.

Twenty steps bring me to the top of the mound and the green concrete box. A strange cylindrical structure like an outsized chimney pokes out of the flat roof, and a radio aerial bristles to my right. A small wooden noticeboard just inside the door informs me that the “attack state” is “black.” Once inside the door, I pass through an airlock—two rubber-sealed, gas-proof doors—and then descend stairs into the heart of the bunker. It is around 4,000 square feet, containing a kitchen, canteen, dormitories, plant room, generator room, telephone exchange, and officers’ room, with a large gallery overlooking the operations room, another level down. This bunker is an entirely different beast than the drafty underground cell in Castleton.

“One-hundred and twenty volunteers and four paid officers were trained up to use this bunker,” says Jake Tatman, who works behind the scenes there. “If nuclear war was likely you’d have everyone working on shifts with 60 staff manning the bunker at any one time.” If a nuclear strike occurred, the door would be locked and the crew inside would prepare for 30 days of tracking radiation and weather, and collating and plotting measurements from the surrounding posts. And just like at Castleton, one poor sod would have to go outside after the blast to retrieve the light-sensitive paper from the Ground Zero Indicator. He or she, however, would have had the added luxury of a shower, to help wash off some radioactive particles.


The York headquarters has been preserved, and includes (clockwise from top left) chairs in the canteen, ROC jackets in the Ladies’ Dormitory, the ROC crest in the canteen, and a telephone in the Operations Room.

This bunker also would have had a few specialists. “During an emergency it was essential that the bunker had at least one engineer, capable of keeping the generator and air conditioning system going,” explains Tatman, outside the diesel generator room. In the gallery, a team of specialist plotters would have sat at a row of desks, listening for information from outlying bunkers and putting it up on rotating Perspex display boards, which could be swiveled around to be viewed by still more specialists in operations below.

Data would be plotted on the triangulation table, and the location of blasts would then be transferred to four large maps on the wall: the current situation, the cumulative situation, the United Kingdom situation, and the European situation. Meanwhile, on the opposite side of the gallery, a group of tellers would pass this information to other group headquarters, as well as government and military facilities. It is through this process, ideally, that the contributions of volunteers at local bunkers like Castleton would make their way into the corridors of power, where the difficult decisions were to be made.


The Operations Room at the York bunker.

At least in theory. In practice, the York bunker might not have survived the first day. “York was the hub of the railway industry and it had four RAF [Royal Air Force] bases, so it would have been a big target,” says Tatman. “The chances are that this bunker wouldn’t exist at all after a nuclear attack.” The volunteers running the more remote observation posts might survive the initial attack, only to have to fend for themselves.

With all of this in mind, utility, survival, and maintenance of a functional society were hopeful, secondary goals for the bunkers. The network was, by design, one of Cold War Britain’s worst-kept secrets, at home and abroad. The very existence of these bunkers, and the willingness of thousands of volunteers to train to defend their country, could have played a role in preventing a nuclear strike from occurring in the first place.

And today, as tensions rise again, it feels like we need to rediscover something of the calm and stoicism that these bunkers were built to encourage. Perhaps we would be more confident if we knew that our friends and neighbors had our backs. Throughout the Cold War, this system—of both bunkers and people—played a significant role in boosting morale and containing fear. Neither of these things seems particularly possible today. The restored York and Castleton sites evoke a kind of nostalgia, for when it at least seemed like ordinary citizens had the power to help each other, even if it was rather illusory. Teapots that don’t pour properly and itchy blankets are important comforts when you feel like there’s a greater purpose to them.

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This post originally appeared on Atlas Obscura and was published September 11, 2018. This article is republished here with permission.

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