From ancient catacombs, those underground passages in which the dead were buried or their remains and bones were preserved, to the modern subway, humans have always traveled underground for brief periods of time. But have entire societies of people ever lived underground?
Tara Santora answers this question in his article on Live Science, saying, yes, But historically it was only during emergencies and when there was no other option, but that has begun to change in recent decades.
Will Hunt, author of “Underground: A Human History of the Worlds Beneath Our Feet”, says “The thing that is important to know about the underground is that we do not belong there. Biologically, physiologically, our bodies are just not designed for life underground.”
Why did people live underground?
Throughout history, Hunt tells Live Science, people have lived temporarily underground for various reasons. When there were no materials to build houses, they dug houses underground.
In places with harsh climates, people went underground in the summer to feel the cold and in the winter to stay warm. People also resorted to living underground to protect themselves from enemies and to stay safe. For example, the ancients built the famous underground cities of Cappadocia in what is now Turkey, to protect themselves from both war and weather.
Hunt says “They were geographically in a very strategic place… they were constantly under attack.” So residents took refuge underground during emergencies, but they didn’t stay there for long, maybe weeks at a time.
The largest underground cities
One of the largest underground cities in Cappadocia is Derinkuyu, which dates to around the seventh or eighth centuries and could have housed about 20,000 people, according to Atlas Obscura.
Geophysicists have found that another recently discovered city in the region spans 5 million square feet (460,000 square meters) and may be 371 feet (113 m) deep, according to National Geographic. If true, this would make the recently found Cappadocia city about a third larger than Derinkuyu.
The underground cities of Cappadocia are an “architectural marvel,” Hunt said. Wells plunged deep into the water table. Holes leading up to the surface acted as ventilation shafts. Layers of protection — including large, circular stones that the ancient people rolled in front of entrances to the city — separated those inside from invaders on the surface.
The underground city of Kaymakli.
Cappadocia region, Turkey.
Living underground in the modern era
Not all subterranean dwellings were as complex as those in Cappadocia, however. People also lived in natural and human-made caves, Hunt noted. Constructed caverns can be found anywhere with the right kind of geology — for example, stone hills made from tuff, a soft volcanic rock that’s easy to dig into.
“They’re very common,” he said. “You find people making cave dwellings all over the world.” Even in modern day Australia, in a town called Coober Pedy, about half the population lives in “dugouts,” or holes carved into the sides of hills, according to Smithsonian Magazine.
Many marginalized people have found shelter below the surface in abandoned infrastructure of modern cities. There are fewer of these “mole people” of New York than there were in the 1980s, but perhaps more than 1,000 unhoused people live in tunnels beneath the streets of the city, Hunt said.
Many homeless people also live in tunnels beneath Las Vegas. And large communities of orphans live under the streets in Bucharest, Romania.
Persuading people to move underground
As more people go to live in cities, more city dwellers may move underground. Countries such as Singapore are exploring options for downward-facing construction into the ground.
The technology to do this already exists, says Eun Hee Lee, an assistant professor of psychology at the University of Nottingham’s Malaysia who studies the psychology of staying underground. The challenge is to convince people to move underground.
In reality, being beneath the earth hasn’t yet been shown to cause negative psychological effects, as long as lighting, room size, ceiling height and other physical attributes of the setting are consistent with aboveground, Lee said.
For example, technology such as lightwells, which allow natural sunlight to brighten underground spaces using materials such as reflective paint, could fight depression that arises from a lack of sunlight. People may feel isolated from their counterparts on the surface, and they may feel a lack of control, but these feelings are manageable, Lee said. However, people still dislike the idea of living belowground.
Lee also believes that people around the world will soon start moving underground, influenced by places that have paved the way such as RÉSO, an underground city in Montreal, Canada that is more than 32 kilometers long and includes shopping malls, offices, hotels and schools.
She says that “Realistically, we will go underground soon. In at least 30 years there will be more work environments and fun places underground. It’s coming, and it’s not just an idea.”