Derinkuyu Underground city
Derinkuyu Underground City is located in the homonymous Derinkuyu district in Nevsehir Province, Turkey. It is on the road between Nevsehir and Nigde, at a distance of 29 km from Nevsehir. It was opened for visitors as of 1969 and to date, only ten percent of the underground city is accessible for tourists. Its eight floors 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 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. The large 55 m ventilation shaft appears to have been used as a well. The shaft also provided water to both the villagers above and, if the outside world was not accessible, to those in hiding.
First built by the Phrygians in the 8th-7th centuries B.C according to the Turkish Department of Culture, the underground city at Derinkuyu 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 3,000 and 50,000 people.
The underground city of Derinkuyu was the hiding place for the first Christians who were escaping from the persecution of the Roman empire. Everything discovered in these underground settlements belongs to the Middle Byzantine Peroid, between the 5th and the 10th centuries A.D. The number of the underground settlements, generally used for taking refuge and for religious reasons, increased during this era. The Christian communities in the region took refuge closing millstone doors when they were subjected to the Arab raids, which started in the 7th. The enemy, unaware of the dangers waiting them inside, usually tried to make the local people leave their shelters by poisoning the wells.
Underground cities in Cappadocia generally had a number of features in common: rooms for food storage, kitchens, churches, stables, wine or oil presses, and shafts for ventilation. The underground city in Derinkuyu, which covers eight levels and extends to a depth of 85 meters, was large enough to shelter thousands of people together with their livestock and food stores.
Other underground cities
Nevsehir Province has several other historical underground cities. The cities and structures are carved out of unique geological formations. They were used by Christians as hiding places during times of persecution and raids. The locations are now archaeological tourist attractions. They remain generally unoccupied. In excess of 200 underground cities containing a minimum of two levels have been discovered in the area between Kayseri and Nevsehir. Some 40 of those containing a minimum of three levels or more. The troglodyte cities at Kaymakli and Derinkuyu, are two of the best examples of habitable underground structures.