Descending Into Beijing's Forgotten Nuclear Shelter
The descent begins behind a shopfront in Qianmen, a few hundred meters from Tiananmen Square. A door that looks like a storeroom opens onto cracked concrete steps, and the noise of the street — car horns, hawkers, the churn of one of the densest cities on the planet — drops away within a few paces. Cold air rises from below. A single torch beam picks out peeling murals, rusted bicycle frames, and pools of standing water that reach the knee. The lights that once lined these corridors are dead, drowned by decades of flooding. On one wall, a faded portrait of Mao Zedong still watches over the dark.
This is Dixia Cheng, the "Underground City" — a nuclear bomb shelter dug by hand beneath the heart of Beijing during the 1970s.
Nobody ever sheltered here from a bomb. No Soviet warhead ever fell. The tunnels were built for a war that arrived only as a fear, and when the fear faded, the city above simply forgot the city below.
That is the truth at the center of this place. Dixia Cheng is not a monument to a catastrophe. It is a monument to the anticipation of one — a physical measurement of how completely a regime believed in its own annihilation. To build it, Beijing mobilized hundreds of thousands of civilians and tore down the 500-year-old imperial walls that had defined the city since the Ming dynasty, feeding centuries of history into the ground as construction fill. The old defenses were demolished to build a new one. Then the new one was never needed.
Why Mao Built an Underground City: The Sino-Soviet Split and the 1969 Nuclear Scare
The Zhenbao Island Clashes and the Fear of a Soviet First Strike
The order came out of a border war on a frozen river. In March 1969, Chinese and Soviet troops fought a series of vicious skirmishes over Zhenbao Island, a scrap of disputed land in the Ussuri River between Manchuria and the Soviet Far East. The clashes killed soldiers on both sides and pushed two nuclear-armed communist giants to the edge of open war.
The alliance between Moscow and Beijing had been rotting for a decade, split by ideology, ego, and the personal contempt between Mao and Khrushchev's successors. Zhenbao turned the split into something that felt like a countdown. Soviet officials floated the idea of a preemptive strike on China's young nuclear program. In Beijing, the leadership took the threat literally and completely. Mao concluded that the Soviet Union might attack at any moment, and that the attack could be nuclear.
His response was not to negotiate. It was to dig.
"Dig Tunnels Deep, Store Grain Everywhere": Mao's Doctrine of Total Civil Defense
The slogan defined the era: "Dig tunnels deep, store grain everywhere, never seek hegemony." It was printed on walls, chanted in work units, and turned into national policy. The logic was blunt. If China could not out-arm the Soviet Union, it would out-survive it. A country that could bury its population and its food supply could absorb a nuclear first strike and keep fighting.
This was civil defense on a scale no Western government attempted. American planners of the same years built discreet, guarded bunkers for the people who mattered most — the Congress at the Greenbrier Bunker, the military command deep inside a mountain. Beijing's answer was different in kind. The plan was not to save the leadership and a chosen few. It was to shovel the entire urban working population underground, and the working population would do the digging themselves.
Cities across China began carving shelters into the earth. Beijing's became the largest and most ambitious of them all.
Digging a City by Hand: 300,000 Workers and the Erasure of Old Beijing
Clerks, Students, and Housewives With Shovels
The workforce was the city itself. Estimates of the number of people who dug Dixia Cheng run from 300,000 upward — factory workers, office clerks, students, housewives, and soldiers of the People's Liberation Army, organized through their work units and neighborhood committees. They dug after their shifts and on their rest days, hauling out earth in baskets and hand-carts, deepening the tunnels through the hard clay beneath Beijing with picks and shovels.
There was almost no heavy machinery. The Underground City was excavated the way the Great Wall had been raised two thousand years earlier: with human muscle, applied in overwhelming numbers, under a state that could compel it. The nickname that stuck — the "Underground Great Wall" — was earned honestly. So was the human cost, measured not in a single disaster but in years of unpaid, exhausting, hand-broken labor by people who had no choice but to volunteer.
Picture the ordinary rhythm of it. A clerk finishes a day of paperwork, eats, and reports to a tunnel mouth hidden behind a shop on his street. He descends into the damp, works a shift underground moving earth by lamplight, and climbs back into the city he is preparing to abandon. He does this for weeks, then months. Above him, the shops stay open. Below him, a second Beijing grows outward in the dark, one basket of clay at a time.
Tearing Down the Ming and Qing Walls for Tunnel Bricks
The tunnels needed brick, and Beijing had brick — in its walls. For five centuries the capital had been ringed by monumental fortifications, the great gray ramparts and gate-towers of the Ming and Qing dynasties, some of the most complete city walls in the world. Through the 1960s and 1970s, they came down.
The demolition served several appetites at once: road-building, subway construction, and the hunger of the shelter program for material. Centuries-old walls, towers, and gates were pulled apart, and the bricks were carted off. The great gates of Xizhimen, Fuchengmen, and Chongwenmen survive today only as the names of subway stops and intersections. Of the imperial ring that once defined Beijing, almost nothing remains standing — a couple of watchtowers at Zhengyangmen and Deshengmen, and one weed-choked stretch of Ming wall preserved by accident near the railway station.
Here is the irony carved into the ground itself. To defend against a foreign bomb, Beijing destroyed the defenses that had protected it for five hundred years, and buried the rubble of imperial China beneath the streets as the skeleton of a shelter that would never be used. The old wall was built to keep armies out. The Underground Great Wall was built to hide the population from the sky. One replaced the other, brick by looted brick.
Inside Dixia Cheng: The Apocalypse City Beneath the Streets
Blast Doors, Hidden Entrances, and Fallout-Resistant Ventilation
The finished complex was enormous and deliberately invisible. It spread across roughly 85 square kilometers under central Beijing, buried between 8 and 18 meters down, with a network of passages whose true length was never officially published — thirty kilometers by the conservative estimates, far more by others. No single authoritative map of the whole system was ever released, which was the point.
Access was concealed by design. At its peak the shelter had around ninety entrances, and nearly all of them were hidden inside ordinary shops along the main streets of Qianmen. A customer might buy cloth or noodles above a trapdoor without ever knowing it. In one shop, a map of the tunnel network was reportedly drawn on the wall in fluorescent ink, invisible in normal light and readable only under a special lamp — a plan hidden in plain sight, and, the story went, invisible to Soviet eyes.
The engineering was built for the worst case. Thick concrete blast doors and waterproof hatches could seal sections against overpressure and flooding. Ventilation systems were designed to filter fallout and to keep the air breathable through a nuclear, biological, or chemical attack. The state claimed the complex could keep its occupants alive underground for months, sustained by stored grain and its own hidden infrastructure.
A Full City for the End of the World
The tunnels were meant to hold a functioning society, not just frightened people crouched in the dark. Planners built classrooms so that children could keep studying underground. They built clinics and reportedly a hospital, a cinema, barbershops, restaurants, warehouses stocked with grain, and — the detail that everyone remembers — a roller-skating rink. If Beijing was going to spend months beneath its own streets, it would not die of boredom while it waited out the apocalypse.
The scale of the ambition was staggering and, at the edges, impossible. Official plans called for sheltering around forty percent of the capital's population underground, with the rest evacuated to the surrounding hills; some government claims stretched to housing all six million residents of the time. Tunnels reportedly linked the leadership compound at Zhongnanhai and the Great Hall of the People to military sites beyond the city, so that China's rulers could slip out while the population went to ground. The arithmetic never quite worked — no hand-dug warren could actually swallow a city that size — but the plan was less an engineering blueprint than a statement of will. The message to the people, and to Moscow, was that China intended to survive at any cost.
The Shelter That Was Never Used: From Cold War Relic to Tourist Curiosity
Forgotten Underground for Twenty Years
The war never came. The Soviet strike that Beijing spent a decade and hundreds of thousands of laborers preparing for never materialized, and as the 1970s ended and relations slowly thawed, the reason for the tunnels evaporated. The Underground City did not close with a ceremony. It simply lost its purpose and slid out of memory.
For roughly twenty years, Dixia Cheng was a rumor. Locals stopped thinking about it. Sections filled with water or were sealed. The blast doors that had been built to hold back a nuclear shockwave now held back nothing but silence.
The site resurfaced as a tourist attraction in 2000, when a portion of the tunnels near Qianmen was opened to the public. For most of that run it drew foreign visitors far more than Beijingers, many of whom had no idea the complex existed beneath their feet. The official tour looped through a short circuit of corridors, past the surviving relics of the era: the portrait of Mao, murals of the volunteers who had dug the tunnels, and slogans fading off the walls — "Dig the tunnels deep," "Prepare for war, prepare for famine." The overall verdict of those who went down was consistent. It was dark, damp, and genuinely eerie.
Flooded, Sealed, and Repurposed Since 2008
Dixia Cheng has been closed to tourists since early 2008, shut for a "renovation" that has never meaningfully ended. In the years since, the accessible tunnels have flooded and decayed, and access has been steadily blocked off. The Underground City as a public site effectively ceased to exist, folded back into the state's control.
The wider network Mao's doctrine created did not die, though. It mutated into something he never imagined. Under Deng Xiaoping's reforms, the government commercialized the vast web of civil-defense shelters and mandated that new buildings include underground space, and by the 1980s the basements of Beijing had filled with hostels, shops, cinemas, and roller rinks. Then came the migrants.
Today an estimated population that ranges from the official figure of around 281,000 to more than a million people lives underground in Beijing — in residential basements and repurposed air-raid shelters, the direct descendants of "dig tunnels deep." The Chinese press unkindly named them the shuzu, the "rat tribe." They are waiters, cleaners, hairdressers, security guards, and kitchen hands, mostly rural migrants shut out of the legal housing market by the hukou registration system, paying a few hundred yuan a month for a windowless room of seven or eight square meters. Many of these rooms are entered through the same thick, air-lock blast doors that were installed to survive a Soviet attack. In 2010 the government banned residential basement rentals on safety grounds and began evicting the underground population by the tens of thousands, a slow clearance that continues unevenly to this day.
The final irony sits in that detail. The shelter Mao built to save the people from a war that never came now stands mostly empty and sealed — while a million of the city's poorest live pressed into the network's smaller cousins, hiding not from bombs but from the cost of the city overhead.
Visiting Beijing's Underground City: What Remains and What You Can See
Dixia Cheng is not a functioning tourist site. The Qianmen tour that operated between 2000 and 2008 has been closed for well over a decade, the entrances demolished or sealed, and there is no reliable public access to the historic core of the Underground City today. Travelers who arrive in Beijing hoping to descend into Mao's nuclear bunker will find locked doors, vanished shopfronts, and vague official answers. Reports of the site being converted to other state uses have circulated for years. Anyone determined to see it should treat every secondhand claim of an "open entrance" with heavy skepticism and never attempt to enter sealed or flooded tunnels, which are genuinely dangerous — waterlogged, unlit, and structurally uncertain.
What can be seen is the world the shelter left behind. The traces are everywhere once you know to look for them: the air-raid-shelter signs on Beijing basements, the civil-defense doors on residential towers, the blank spaces on the map where the imperial gates used to stand. A short stretch of the old Ming wall survives at the Ming City Wall Ruins Park near the railway station, the physical negative of the tunnels — the walls that were not torn down to feed the dig. Above it all sits Tiananmen Square, the ceremonial center of the state that ordered the whole enterprise, a few minutes' walk from where the tour once began.
Standing over Dixia Cheng means standing over an emotion rather than an event. There is no massacre here, no single day of horror to mark. There is only the vast physical residue of fear — the sheer tonnage of earth moved by hand because a government was convinced the sky was about to fall. It belongs to the same Cold War impulse that drove the Americans to hollow out mountains and freeze Camp Century into the Greenland ice, and that packed Plokštinė with the Soviet missiles this shelter was meant to outlast. Beijing's version was the most human and the most tragic of them, because it was built not by engineers and specialists but by the ordinary people it was meant to save — people who dug their own refuge from a catastrophe that stayed, mercifully, imaginary. The bombs never came. The tunnels remain, filling quietly with water in the dark, the largest thing a city ever built and then chose to forget.
FAQ
What is Dixia Cheng, Beijing's Underground City?
Dixia Cheng is a Cold War-era bomb shelter and tunnel network dug by hand beneath central Beijing during the 1970s. Mao Zedong ordered its construction after border clashes with the Soviet Union raised the fear of a nuclear attack. Spread across roughly 85 square kilometers between 8 and 18 meters underground, it was designed to shelter a large share of the capital's population, complete with classrooms, clinics, grain stores, and even a roller-skating rink. It was never used for its intended purpose and has been closed to the public since 2008.
Why did Mao build the Beijing Underground City?
The trigger was the 1969 Sino-Soviet border conflict, a series of armed clashes over Zhenbao Island that pushed the two communist powers toward open war. Soviet officials openly discussed a preemptive strike on China's nuclear program, and Beijing's leadership took the threat of nuclear attack seriously. Mao's response was captured in the slogan "dig tunnels deep, store grain everywhere, never seek hegemony," a national civil-defense policy meant to let China absorb a nuclear first strike and survive. Dixia Cheng was the largest of the shelters built under that doctrine.
Who built Dixia Cheng and how?
The Underground City was excavated almost entirely by hand by the citizens of Beijing. Estimates of the workforce run from around 300,000 upward, including factory workers, office clerks, students, housewives, and soldiers of the People's Liberation Army, organized through their work units. They dug after their shifts using picks, shovels, baskets, and hand-carts, with almost no heavy machinery. Much of the brick used to line the tunnels came from Beijing's demolished Ming and Qing city walls, which were pulled down during the same era.
Can you visit Beijing's Underground City today?
Dixia Cheng is not currently open to tourists. A section near Qianmen operated as a tourist attraction between 2000 and 2008, drawing mostly foreign visitors, but it was closed for "renovation" in early 2008 and has never meaningfully reopened. Entrances have been demolished or sealed, the accessible tunnels have flooded, and reports suggest parts of the complex have been repurposed by the state. Travelers should treat any secondhand claim of an open entrance with skepticism and never attempt to enter sealed or flooded tunnels.
Was the Beijing Underground City ever used in a war?
No. The Soviet nuclear strike that the shelter was built to survive never came, and Dixia Cheng was never used for an air raid or any wartime emergency. As Sino-Soviet tensions eased at the end of the 1970s, the complex lost its purpose and faded from public memory for roughly two decades before briefly opening as a curiosity for tourists.
Do people still live underground in Beijing?
Yes, though not inside the historic Dixia Cheng tour route itself. Mao's civil-defense doctrine left Beijing with a vast network of basement shelters, and under later economic reforms these spaces were commercialized. Today an estimated population ranging from official figures of around 281,000 to more than a million people — nicknamed the "rat tribe" — lives in residential basements and former air-raid shelters, mostly migrant workers priced out of the legal housing market. Many enter their rooms through the same blast doors built to survive a Soviet attack, and authorities have been evicting these dwellers since a 2010 ban on basement housing.
Sources
The Sino-Soviet Border Conflict: Deterrence, Escalation, and the Threat of Nuclear War in 1969 — Michael S. Gerson, Center for Naval Analyses (2010)
The Sino-Soviet Border Conflict, 1969 — National Security Archive, George Washington University (2021)
Beijing's Underground City (Dixia Cheng) — GlobalSecurity.org (2019)
The Last Days of Old Beijing: Life in the Vanishing Backstreets of a City Transformed — Michael Meyer (2008)
The Walls and Gates of Peking — Osvald Sirén (1924)
The Extreme Primacy of Location: Beijing's Underground Rental Housing Market — Annette M. Kim, Cities (2016)
Beijing's Rat Tribe — Annette Kim and Sim Chi Yin, Foreign Affairs (2016)
Beijing's Rat Tribe: The Chinese Dream Goes Underground — Sim Chi Yin, Pulitzer Center (2015)
China: Beijing's Underground City — The Caravan (2011)
Meet the 'Rat Tribe' Living in Beijing's Underground — CNN (2015)
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