Guy Knocks Down His Basement Wall and Discovers Ancient Underground City That Once Housed 20,000 People

On the Anatolia plateau in Turkey, a volcanic landscape sculpted by erosion sports a succession of mountain ridges, valleys and pinnacles known as “fairy chimneys” or hoodoos, Göreme National Park and the Rock Sites of Cappadocia cover the region between the cities of Nevşehir, Ürgüp and Avanos, the sites of Karain, Karlık, Yeşilöz, Soğanlı and the subterranean cities of Kaymaklı and Derinkuyu. Image credit: MrHicks46
Derinkuyu reached its peak in the Byzantine period (about 395 CE to 1453 CE). It was then that the place was made into a labyrinth of tunnels, chambers, stairs, passageways and rooms, covering 445 kilometers² (172 miles²) altogether. The vast network thus created contains concealed entrances, wells and water channels – and even ventilation shafts to provide residents with enough oxygen.