The history of underground cities is a complex and meandering one, ranging from the Ancient Era in the Middle East and Europe to those sunk during the height of Cold War paranoia, such as the bunker complexes of Cheyenne Mountain or Beijing’s Underground City. Now, we’re not talking about mole people (or even their modern namesakes).
The primary reason for digging underground cities in the ancient world was for protection, as the spaces could be closed by rolling heavy boulders across the entrances. So-called “fairy chimneys” allowed for the ventilation of the chambers, and the smoke from within would rise to the surface, many miles away from the cities.
There are also more recent underground cities, some of which are simply underground shopping centers or networks of tunneled roads, like those in Vancouver and Tokyo, as well as others which will begin to be built only in the future, due to the constraints of small islands and the opportunities for vast wealth, which are being considered in Singapore and in Hong Kong. Here are five subterranean metropolises where humans seeking refuge found it by digging into the earth.
Setenil De Las Bodegas
Some of the oldest known underground cities are in Spain, with the village of Setenil de las Bodegas showing evidence of occupation dating at least from the Roman invasion of Iberia in the first century CE, and possibly from much earlier. The town has an especially florid history, having been occupied by the Romans, as well as being a Moorish stronghold from the 12th century until the early 15th, when it was finally taken during the Christian Reconquest. The town is not what you would imagine an underground city to be, however, as it is mostly above-ground, with large boulders overhanging the houses.
The cities of Özkonak, Derinkuyu, and Kaymaklı in Cappadocia, Turkey, are some of the most complete (and most underground) of our underground cities. Denrikuyu is estimated to have once been capable of housing 20,000 people, and actually connects to Kaymakli via an underground tunnel, eight kilometers long. The cities are just three of a huge number of underground refuges in Turkey, and each is suggested to have been occupied since antiquity.
They contain churches, storerooms, and staggering staircases, as well as artefacts of Zoroastrianism, Byzantine Christianity and of more mundane activities, with oil presses and gigantic storerooms occupying large portions of the site.
The history of the region provides an explanation of why so many underground cities exist in Turkey—not only was the region under constant pressure from foreign invaders (the Greeks, Persians, Scythians and Romans all fought over this territory for millennia), but the region also sheltered Christians during the persecutions of the Roman Empire and of the area’s later Muslim overlords.
Petra, in Jordan, was settled as early as 312 BCE, although the area around the city had been settled around 7000 BCE. It is mentioned in accounts of Egyptian military campaigns, as well as in the Biblical book of Exodus, as the country of the Horites, with the city itself referred to as Sela, or “the cleft in the rock.”
Archaeologists believe that the city was originally settled as a means to control the natural reservoirs that form beneath it, or possibly as a burial site. Writers such as Pliny the Elder recognized Petra as a major trade site between Gaza and Syria, and then on into Rome, which allowed the city to prosper. It wasn’t until its conquest by Rome in 106 CE that the city began to enter a slow decline.
The site was forgotten, until 1812, when it was rediscovered by Swiss explorer Johann Ludwig Burckhardt. The site is now on the UNESCO Intangible Cultural Heritage List, and the agency declared Petra to be “one of the most precious cultural properties of man’s cultural heritage.”