While some are trying to find a place to live in space, others are trying to find safety underground, namely in basements and tunnels. The difference between them is that one looks upwards and the other downwards, and the goal is the same: escaping from disasters, wars, and pandemics.
Physicist Stephen Hawking recommended before his death to prepare to live on other planets or under the surface of the earth.
In Tunisia, specifically in the Matmata region, some Berbers live in caves called Targlodayites, meaning cave dwellers.
In Turkey, the ancients built the underground cities of Cappadocia, in addition to other cities that can accommodate more than 200,000 people.
As for Singapore, it also started projects to build small underground cities since 2001, while one million Chinese live underground.
Underground Cities Project
And after the limitation of horizontal and vertical expansion above the ground became clear, many regions of the world began to grow downwards, and vast underground spaces were exploited in the construction of commercial markets, metro stations and parks, as is the case in:
• Mexico City
• New York
Confirmed information indicates that there are complete and equipped underground cities built by the Soviet Union, the United States, Germany and most of the Scandinavian countries that are habitable.
These cities, which have been in vogue since the fifties of the twentieth century, are immune to nuclear and biological attacks.