Secret Cities

We all lose things — keys, wallets, patience — but how do you lose an entire city? Hear the stories of three American towns built in a hurry but kept off the map, secure Soviet enclaves known by their post codes, ancient cities found by modern technology, and the ingenious engineering of underground dwellings.

In 1943, three ordinary-looking US cities were constructed at record speed, but left off all maps. Oak Ridge, Tennessee; Richland, Washington; and Los Alamos, New Mexico held laboratories and sprawling industrial plants, as well as residential neighborhoods, schools, churches, and stores. The three cities had a combined population of more than 125,000 and one extraordinary purpose: to create nuclear weapons as part of the Manhattan project, the U.S. military’s initiative to develop nuclear weapons.

Their design was driven by unique considerations, such as including buffer zones for radiation leaks or explosions. In each case, there were natural features, topographical features, that were considered to be favorable. In all three cases, they were somewhat remote—in the case of Hanford and Los Alamos, very remote—which offered a more secure environment, of course. But also, in the event of a disaster, an explosion or a radiation leak, that would also minimize the potential exposure of people outside the project to any sort of radiation danger. The sites were selected far from one another in case German or Japanese bombers somehow managed to penetrate that far into the United States, it would be harder for them in a single bombing run to take out more than one facility. K-25 plant at Oak Ridge, which was where they enriched uranium using the gaseous diffusion method, was the largest building in the world under a single roof, spanning more than 40 acres.

Before you being any building project, you have to clear the site of things like trees, high spots, people. In 1942, the government approached the families that lived near the Clinch river in Tennessee, some of whom had farmed there for generations, and kicked them out, telling them the land was needed for a “demolition range,” so as to scare off hold-outs with the threat of adjacent explosions. The town scaled up fast. Oak Ridge was initially conceived as a town for 13,000 people but grew to 75,000 by the end of the war, the biggest of the secret cities. The laboratories took up most of the space, but rather than constructing basic dormitories for employees, the architects and designers settled on a suburban vision. To pull this off quickly and secretly, the architects relied on prefabricated housing, in some cases, a house might come in two halves on the back of a truck to be assembled on-site. These were called “alphabet houses;” A houses were the most modest (read: tiny), while D houses included dining rooms. Housing was assigned based on seniority, though allowances were sometimes made for large families.

And race. This was the early 40’s, after all. The secret suburbs for factories manufacturing megadeaths were segregated by design. Their houses were called “hutments,” little more than plywood frames without indoor plumbing, insulation or glass in the windows. Though two of the first public schools in the south to be desegregated were in Oak Ridge. They even threatened to secede from Tennessee in order to desegregate, so at least there’s that. There were white families in the hutments as well and all of the residents of that lower-class neighborhood were under more surveillance and stricter rules than the families in better housing. Married couples may be forbidden to live together. By the end of the war, most of the white families had been moved out of the hutments and but many of the African American families continued to live in the basic dwellings until the early 1950s.

These towns didn’t appear on any official maps, and visitors were screened by guards posted at the entrances. Anyone over 12 had to have official ID. Firearms, cameras, and even binoculars were prohibited. Billboards were installed all over town to remind workers to keep their mouths shut about their work, even though most workers knew very little about the project’s true scope. For example, you job may be to watch a gauge for eight hours and flip a switch if it goes to high. You don’t know what you’re measuring or what the machine is doing. All you’ve been told is to flip the switch when the needle hits a certain number. In Los Alamos and Richland, the entire neighborhood may have the same mailing address. At Oak Ridge, street addresses were designed to be confusing to outsiders. Bus routes might be called X-10 or K-25 while dorms had simple names such as M1. There were no signs on buildings. The town was full of such ciphers, and even employees didn’t know how to decode them all. The use of words such as “atomic” or “uranium” was taboo lest it tip off the enemy.

When the US dropped the atom bomb on Hiroshima, Japan, in 1945, the city’s secret was out. Many residents celebrated at this turning point in the war, but not all. Mary Lowe Michel, a typist in Oak Ridge, is quoted in an exhibit on display now at the National Building Museum in DC: “The night that the news broke that the bombs had been dropped, there was joyous occasions in the streets, hugging and kissing and dancing and live music and singing that went on for hours and hours. But it bothered me to know that I, in my very small way, had participated in such a thing, and I sat in my dorm room and cried.” All three cities remained part of the military industrial complex, continuing to work on nuclear weapons during the cold war as well as broader scientific research. Today Oak Ridge is heavily involved in renewable energy, minus the barbed wire fence.

For most of the twentieth century, if the US was doing it, so was the USSR. We had closed cities to build nuclear weapons, and so did the Soviet Union. We had three, they had….lots. Like, a lot a lot. Like, multiple screens on the Wikipedia list. Where the US began to open its closed cities after the war, the USSR was building more and more, and not just for nuclear weapons. These closed cities were nicknamed “post boxes,” because they would be named for the nearest non-secret city and the end of their post code; or simply “boxes” for their closed nature. During the two decades following World War II, dozens of closed cities were built around the country. Some were naukogradi (“science cities”) or akademgorodoki (“academic cities”), while others developed military technology and later spacecraft. The official name was closed administrative-territorial formations or zakrytye administrativno-territorial’nye obrazovaniya, or ZATOs.

The cities were largely built by slave labor from the Gulag prison camps, which at the time accounted for 23% of the non-agricultural labor force in the Soviet Union. They were guarded like gulags, too – surrounded by barbed wire and guards, with no one was allowed to enter or leave without official authorization. Many residents did not leave the city once between their arrival and their death. That being said, the captive residents enjoyed access to housing, food, and health care better than Soviet citizens elsewhere. While most towns in the Soviet Union were run by local communist party committees, military officials oversaw the secret cities that would eventually be home to over 100,000 people. Even during construction, officials were ordered to use trusted prisoners only, meaning no Germans, POWs, hard criminals, political prisoners. Nevertheless, even living alongside Gulag prisoners, residents believed they were making a valuable contribution to their country. Nikolai Rabotnov, a resident of Chelyabinsk-65, remembered, “I was sure that within our barbed labyrinth, I inhaled the air of freedom!”

Arzamas-16, today known by its original name Sarov, was one of the most important sites in the early development of the first Soviet atomic bomb and hydrogen and was roughly the Soviet equivalent of Los Alamos. Scientists, workers, and their families enjoyed privileged living conditions and were sheltered from difficulties like military service and economic crisis. Leading researchers were paid a very large salary for those times. Chelyabinsk-65 or Ozersk was home to a plutonium production plant similar to the American facilities built at Richland. Located near a collective farm in the southern Ural Mountains, Chelyabinsk-65 was more or less built from nothing, where Arzamas-16 was an existing town that was taken over. After the basics of the city were completed, early years were very difficult for the residents. The cities lacked basic infrastructure and suffered from high rates of alcoholism and poor living conditions. The Mayak Plutonium Plant dumped nuclear waste in the nearby Techa River, causing a health crisis not only for the residents of Chelyabinsk-65 but for all the villages which ran along it.

Conditions at Chelyabinsk-65/Ozersk would not improve until after the death of Joseph Stalin in 1953. You remember that story, it was in our episode For Want of a Nail. Owing to the plutonium plant, Chelyabinsk-65 is still one of the most polluted places in the world. Some residents refer to it as the “graveyard of the Earth.” Somehow, though, it’s considered a prestigious place to live where. When the government polled residents after the Cold War had thawed over whether to open the city, they voted to keep it closed. In fact, half of the nuclear scientists said they would refuse to stay if it was opened. As one resident explained, “We take pride in the fact that the state trusts us enough to live and work in Ozersk.”

In 1991, the Soviet Union officially disbanded and its fifteen republics became independent, four of which had nuclear weapons deployed on their territories. This was of great concern to the West, as these newly formed nations did not have the financial or technological means to properly store and safeguard these weapons. With budgets a fraction of what they were in the decades before, the standard of living in the ZATOs quickly declined. Security went with it, as the soldiers who guarded the ZATOs also saw their wages slashed.

With little prospect of employment and limited security, scientists suddenly had the freedom not only to leave their cities but to leave the country. Fear quickly spread in the United States that they could help develop nuclear programs in other countries, such as Iran. In 1991, the Nunn-Lugar Act financed the transportation and dismantlement of the scattered nukes to not only reduce the number of nuclear weapons in the world but to provide the scientists with proper employment. One result of this effort was the International Science and Technology Center in Moscow, which employed many former atomic scientists on non-weapons programs and still exists today.

If you need to hide a city from your enemies, you’d do well to move it underground. Built in the late 50s in Wiltshire, England, the massive complex, codename Burlington was designed to safely house up to 4,000 central government personnel in the event of a nuclear strike. In a former Bath stone quarry the city was to be the site of the main Emergency Government War Headquarters, the country’s alternative seat of power if the worst happened. Over 2/3mi/1km in length, and boasting over 60mi/97km of roads, the underground site was designed not only to accommodate the Prime Minister, the Cabinet Office, civil servants and an army of domestic support staff.

Blast proof and completely self-sufficient the secret underground site could accommodate up to 4,000 people in complete isolation from the outside world for up to three months. Though it was fortunately never used, the grid of roads and avenues ran between underground hospitals, canteens, kitchens, warehouses of supplies, dormitories, and offices. The city was also equipped with the second largest telephone exchange in Britain, a BBC studio from which the PM could address the nation and a pneumatic tube system that could relay messages, using compressed air, throughout the complex. An underground lake and treatment plant could provide all the drinking water needed. A dozen huge tanks could store the fuel required to keep the generators in the underground power station running for up to three months. The air within the complex could also be kept at a constant humidity and heated to around 68F/20C degrees.

The complex was kept on standby in case of future nuclear threats to the UK, until 2005, when the underground reservoir was drained, the supplies removed, the fuel tanks were emptied and the skeleton staff of four were dismissed.


Some cities were not secret in their heyday, but were lost to time until recently. In what’s being hailed as a “major breakthrough” for Maya archaeology in February 2018, researchers have identified the ruins of more than 60,000 buildings hidden for centuries under the jungles of Guatemala. Using LiDAR, or Light Detection And Ranging, scholars digitally removed the tree canopy from aerial images of the area, revealing the ruins of a sprawling pre-Columbian civilization that was far more complex and interconnected than most Maya specialists had supposed. Mounted on a helicopter, the laser continually aims pulses toward the ground below, so many that a large number streak through the spaces between the leaves and branches, and are reflected back to the aircraft and registered by a GPS unit. By calculating the precise distances between the airborne laser and myriad points on the earth’s surface, computer software can generate a three-dimensional digital image of what lies below. To put the density of this jungle into perspective, archaeologists have been searching the area on foot for years, but did not find a single man-made feature.

“LiDAR is revolutionizing archaeology the way the Hubble Space Telescope revolutionized astronomy,” said Francisco Estrada-Belli, a Tulane University archaeologist and National Geographic Explorer. “We’ll need 100 years to go through all [the data] and really understand what we’re seeing.” The project mapped more than 800 sq mi/2,100 sq km of the Maya Biosphere Reserve in the Petén region of northern Guatemala, producing the largest LiDAR data set ever obtained for archaeological research. The old school of that held that Mayan civilization existed as scattered city-states, but these findings suggest that Central America supported an advanced civilization that was, with as many as 14 million people at its peak around 1,200 years ago, comparable to sophisticated cultures like ancient Greece or China. The LiDAR even revealed raised highways connecting urban centers and complex irrigation and agricultural terracing systems. And that was without the use of the wheel or beasts of burden

Despite standing for millennia, these sites are in danger from looting and environmental degradation. Guatemala is losing more than 10 percent of its forests annually, and habitat loss has accelerated along its border with Mexico as trespassers burn and clear land for agriculture and human settlement. “By identifying these sites and helping to understand who these ancient people were, we hope to raise awareness of the value of protecting these places,” Marianne Hernandez, president of the Foundation for Maya Cultural and Natural Heritage.

Lidar has also helped scientists to redraw a settlement located on the outskirts of Johannesburg, South Africa, and it tells the beginnings of a fascinating story. Scientists from the University of Witwatersrand believe the newly discovered city was occupied in the 15th century by Tswana-speaking people who lived in the northern parts of South Africa. Many similar Tswana city-states fell during regional wars and forced migration in the 1820s, and there was little oral or physical evidence to prove their existence. Though archaeologists excavated some ancient ruins in the area in the 1960s, they couldn’t comprehend the full extent of the settlement. By using LiDAR technology, the team was able to virtually remove vegetation and recreate images of the surrounding landscape, allowing them to produce aerial views of the monuments and buildings in a way that could not have been imagines a generation ago.

Using these new aerial photographs, they can now estimate that as many as 850 homesteads had once existed in and around the city they’ve given the temporary designation of SKBR. It’s likely that most homesteads housed several family members, meaning this was a city with a large population. There are also stone towers outside some homesteads, as high as 8ft2.5m high with bases 16ft/5m wide. The academics believe these may have been bases for grain bins or even burial markers for important people. There is also evidence of several refuse dumps that may evince a certain level of wealth and power in the region.

Though the team estimates they are still another decade or two away from fully understanding the city’s inhabitants and how the city came to be, and ceased to exist.

Modern technology has also helped us find an ancient city in Cambodia. Constructed around 1150, the palaces and temples of Angkor Wat were, and still are, the biggest religious complex on Earth, covering an area four times larger than Vatican City. In the 15th Century, the Khmer kings abandoned their city and moved to the coast. They built a new city, Phnom Penh, the present-day capital of Cambodia. Life in Angkor slowly ebbed away. Everything made of wood rotted away; everything made of stone was reclaimed by the jungle.

An international team, led by the University of Sydney’s Dr Damian Evans, was able to map out /370 sq km around Angkor in unprecedented detail in less than two weeks – no mean feat given the density of the jungle. Rampant illegal logging of valuable hardwoods had stripped away much of the primary forest, allowing dense new undergrowth to fill in the gaps. It was unclear whether the lasers could locate enough holes in the canopy to penetrate to the forest floor. The prevalence of landmines from Cambodia’s civil war are another area where shooting Lidar from a helicopter really shines. The findings were staggering. The archaeologists found undocumented cityscapes etched on to the forest floor, with remnants of boulevards, reservoirs, ponds, dams, dikes, irrigation canals, agricultural plots, low-density settlement complexes and orderly rows of temples. They were all clustered around what the archaeologists realized must be a royal palace, a vast structure surrounded by a network of earthen dikes—the ninth-century fortress of King Jayavarman II. “To suspect that a city is there, somewhere underneath the forest, and then to see the entire structure revealed with such clarity and precision was extraordinary,” Evans told me. “It was amazing.”

These new discoveries have profoundly transformed our understanding of Angkor, the greatest medieval city on Earth. Most striking of all was evidence of large-scale hydraulic engineering, the defining signature of the Khmer empire, used to store and distribute seasonal monsoon water using a complex network of huge canals and reservoirs. Harnessing the monsoon provided food security – and made the ruling elite fantastically rich. For the next three centuries they channelled their wealth into the greatest concentration of temples on Earth. Angkor was a bustling metropolis at its peak, covering /1,000 sq km; It would be another 700 years before London reached a similar size.

Bonus fact: and not to be a pedant, but “monsoon” refers no to the heavy rains in the rainy season from May to September, but to the strong, sustained winds that bring them.

Some cities are hidden, not for reasons of subterfuge or dereliction, but by necessity. If the place you live would politely be described as uninhabitable, say the Australian outback with summer temperatures of 120 degrees, a viable option is to go underground. Such is the set-up of the town of Coober Pedy, which sounds like the adorable name your toddler gives the new dog and you just kinda go with it. On the surface, the area looks like a ghost town, with few buildings and many of them abandoned. Most of the 3500 residents live below the surface, in burrowed out of caves.

Coober Pedy was established in 1915 following the discovery of opal there, which led to a mining boom as people came in search of their fortune. The name Coober Pedy is an anglicized version of the Aboriginal words kupa-piti, commonly assumed to mean “white man in a hole.” Among those first-comers were soldiers returning from World War I, who knew how to dig, and live in, trenches. The early days were like the gold rush in Wild West. People who found opal were said to have slept next to their claims with guns to ward off would-be thieves. The boom was followed by a leveling off, with fewer people committing to the financial uncertainty and hardships of that life.

An astounding 80% of the world’s opal comes from the area, but that wealth is nothing to the sun. It don’t care; it’s going to continue with the Mad Max motif. People fought back a century ago with ‘dugouts,’ caves bored into the sandstone hillsides. As bigger, more powerful machinery arrived, the mining, and the homes, went deeper. It may be 115 degrees F/47C outside, but it’s only 74F/23C underground. Since then, the underground town has expanded and become more sophisticated. The town has several underground hotels and B&Bs, a church, a gift shop, a museums, a casino, and, of course, a pub.

Entrances are usually at street level, and the rooms extend towards the back into the hill. All rooms are ventilated via narrow vertical shafts, with wider shafts used to bring in light. You can see the top of those shafts poking out of the hills everywhere in and around Coober Pedy. That are the give away signs, the only hint of the hundreds of underground homes. The underground homes are conceptually simple to renovate. Need a bookshelf? Carve one out. Having a baby and need a nursery? Dig out a new room? The tunneling machines leave an attractive pattern on the walls, and the sandstone itself has beautiful maroon and rose coloured swirls, so warm and friendly, it’s absolutely gorgeous. When the building work is finished the sandstone is sealed with a clear sealer, otherwise an underground home would be rather dusty.

Underground cities predate modern mining equipment considerably. Several million years ago, volcanic eruptions spewed layer after layer of ash, called tufa, over modern-day Turkey, which cemented over time into a soft, easily carvable, yet relatively stable rock. Inhabitants of ancient Anatolia realized that they could carve out their homes right into the hillsides and underground. Derinkuyu is one of the many rock-cut dwellings in the region. It is the deepest, at as much as 250 feet or about 25 stories underground with a capacity for up to 20,000 people. This multi-leveled city contained everything a population would need to survive the invasions that seem to typify its history. The Cappadocian region had been a valuable trade hub since 2500 BCE through early association with their Assyrian neighbors. Many tribes and, later, large governments, have aspired to control Anatolia, leading to millennia of invasion and conquest by different groups. Residents used the underground city for refuge into the 20th century, until the early 1900s when Turks massacred hundreds of thousands of Greeks and later forced all the remainders to leave.

The age of Derinkuyu and who built it are uncertain. The earliest known mention in writing of underground cities in the Cappadocia kingdom came from a Greek historian-soldier named Xenophon in 370 BCE. Xenophon spent time and traveled throughout the region. In his work, Anabasis he says: “The houses here were underground, with a mouth like that of a well, but spacious below; and while entrances were tunnelled down for the beasts of burden, the human inhabitants descended by a ladder. In the houses were goats, sheep, cattle, fowls, and their young; and all the animals were reared and took their fodder there in the houses.”

Within the enormous eighteen levels of the city, only eight of which are currently accessible, researchers found kitchens, bedrooms, bathrooms, food storage rooms, oil and wine presses, wells, weapons storage areas, churches, schools, tombs, and domestic animal stables. Small spaces turned out to be rock-cut tombs, while large spaces provided the ideal rooms for community meetings and schools. More than fifty ventilation shafts brought in air from above, while thousands of smaller ducts distributed that air throughout the entire city. Some archaeologists believe that an 8-kilometer long passageway connects Derinkuyu to another underground city, suggesting was some degree of cooperation between the various civilizations of the Cappadocia region.

The people who built Derinkuyu designed their city as a refuge. Their doors were large discs of stone that covered entrances and passages during raids. Because the doors only opened and closed from the inside, the inhabitants within the complex had complete control. Holes in the middle of the door may have allowed archers to shoot out. Each level connected to the next level by a hallway with a similar stone door. Narrow passages forced people to go through in single file, making it easier to defend against incoming soldiers. The underground city had a water containment system that also took safety as a consideration. It appears that one of the main ventilation shafts also served as a large well. However, the wells within the city did not all link together, nor did they all go to the surface, which protected the inhabitants from invaders who might think to poison the entire water system from the outside. All that 3,000 years before blueprints.

And that’s where we run out of ideas, as least for today. There’s no telling how many more ancient cities have been reclaimed by nature and are waiting to be discovered, or how many secret mid-century cities have yet to be opened to the public. As a personal bonus, writing today’s episode reminded me of an obscure cartoon from the early 80’s called Mysterious Cities of Gold. Give me an enthusiastic wave on our social media, FB, IG if you remember that, or if there is a real secret city you were expecting to hear about, let me know. Thanks for spending part of your day with me.


A Lost African City Has Just Been Discovered by Scientists

Derinkuyu: The Tumultuous History of Turkey’s Underground City

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