Derinkuyu, Turkey, underground city. There are about 600 outside doors to the city, hidden in the courtyards of surface dwellings. The underground city is approximately 85m deep. It contains all the usual rooms found in an underground city (stables, cellars, storage rooms, refectories, churches, wineries etc.) Apart from these, a large room with a barrel vaulted ceiling on the second floor was a missionary school, the rooms to the left being study rooms.
