Derinkuyu Underground City
The Derinkuyu underground city, located in the Derinkuyu district, is a multi-level ancient underground city extending to a depth of approximately 85 meters (279 ft). It is large enough to accommodate up to 20,000 people. It is the largest excavated underground city in Turkey and one of several underground complexes found in Cappadocia. The city was carved into the Kızılkaya ignimbrites.
The underground city in Derinkuyu could be closed from the inside with large stone doors. Each floor could be closed off separately. The city could house up to 20,000 people and had amenities found in other underground complexes across Cappadocia, such as wine and oil presses, stables, cellars, storage rooms, refectories, and chapels.
In the Derinkuyu complex, there is a spacious room on the second floor with a barrel-vaulted ceiling that is reported to have been used as a religious school, while the rooms to the left were classrooms. A series of vertical staircases starting between the third and fourth floors leads to a cruciform church on the lowest (fifth) level.
According to the Ministry of Culture, the caves might have been initially constructed by the Phrygians in the 8th–7th centuries BC in the soft volcanic rock of the Cappadocia region. When the Phrygian language died out in Roman times, replaced by its close relative, the Greek language, the inhabitants, now Christian, expanded their caves into deep multi-level structures, adding chapels and Greek inscriptions.
The city at Derinkuyu was fully developed during the Byzantine era when it was heavily used for protection against Muslim Arabs during the Arab-Byzantine wars (AD 780–1180). The city was connected to other underground cities by kilometers of tunnels. Some artifacts found in these underground settlements belong to the Middle Byzantine Period, between the 5th and 10th centuries. These cities continued to be used by Christian locals as protection against the Mongolian incursions of Timur in the 14th century.
In 1963, the tunnels were rediscovered after a local resident found a mysterious room behind a wall in his home. Further excavation revealed access to the tunnel network. The site was opened to visitors in 1969, and a significant portion of the underground city is currently accessible for tours.