The Derinkuyu Underground Cities Are All Over the World — Survived Ancient Cataclysm

The underground city in Turkey named Derinkuyu is 10 floors deep and can house thousands of people indefinitely, with flowing water, sanitation, and air shafts to the surface. It was discovered in the 1960s, but now hundreds more such ancient underground shelters/cities are being found everywhere.

SOURCE: https://www.brighteon.com/28b16ef2-4590-457e-b32e-832f059a295f