7. Derinkuyu, Turkey – Underground City
The Cappadocia region features unique rock formations that ancient Turks used to carve homes into.
The 5,000-year-old city Derinkuyu boasts a network of tunnels that connect the various parts of this subterranean city, spread out over 11 underground levels.
There are hundreds of entrances, making you feel like a little ant in an ant hill.