Derinku

This is an entire underground city in Turkish Cappadocia, carved out of soft volcanic rock. It reaches about 85 meters deep and has several levels - at one time, up to 20,000 people along with livestock and supplies could hide here.

The first caves were cut here by the Phrygians back in the 8th-7th century BC, and it was expanded to a full-fledged multi-story city already during the Byzantine era. Later, Christians hid here from the Mongols, and then from the Ottomans.

Stone millstone doors, which covered each level separately, a 55-meter ventilation shaft, which at the same time served as a well, as well as stables, warehouses, presses for wine and oil, and a church on the lowest level.

Yes, Derinkuyu is connected to the nearby underground city of Kaimakli by an 8-9 kilometer long tunnel. However, it is impossible to walk through it today - about half of Derinkuy itself is open to tourists.

By chance: in 1963, a local resident came across the passage while renovating his own house. The city was opened to visitors in 1969.