Are there any underground cities?
Are there any underground cities? The cities of Özkonak, Derinkuyu, and Kaymakli 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.
Do secret cities exist?
Some cities are so top-secret they can't even be found on a map. Others are padlocked, hidden in the forest, or buried deep underground. From Poland's 800-year-old Wieliczka Salt Mines to America's WWII mystery towns, SPYSCAPE explores some of the world's most intriguing secret cities.