One of the characteristics of Cappadocia is having plenty of underground cities. The biggest and deepest is Derinkuyu Underground City. There are eight floors and extend at a depth of approximately 85 m.
The underground city at Derinkuyu has all the usual amenities found in other underground complexes across Cappadocia, such as wine and oil presses, stables, cellars, storage rooms, refectories, and chapels. Unique to the Derinkuyu undergorund city complex and located on the second floor is a spacious room with a barrel vaulted ceiling. It has been reported that this room was used as a religious school and the rooms to the left were studies. Between the third and fourth levels is a vertical staircase. This passage way leads to a cruciform church on the lowest level.
First built by the Phrygians in the 8th–7th centuries B.C according to the Turkish Department of Culture, the Derinkuyu underground city was enlarged in the Byzantine era. The city could be closed from inside with large stone doors. With storerooms and wells that made long stays possible, the city had air shafts which are up to 100 feet (30 m) deep. Derinkuyu is the largest excavated underground city in Turkey. The complex has a total 11 floors, though many floors have not been excavated. It has an area of 2,000 square feet, with a possible total area of 7,000 square feet (650 m2). Each floor could be closed off separately. The city was connected with other underground cities through miles of long tunnels. The city could accommodate between 20,000 and 50,000 people.
Derinkuyu is by no means the only such city you can visit here. There are actually 40 or so subterranean settlements in the area although only a few are open to the public.