With huge rolling stone doors, the underground city at Derinkuyu could be sealed off from the inside. Each floor could have its own door closed.
The city had facilities like wine and oil presses, stables, cellars, storage rooms, refectories, and chapels that were also found in other underground complexes throughout Cappadocia. It could house up to 20,000 people.
A large room with a barrel-vaulted ceiling, exclusive to the Derinkuyu complex, is found on the second floor. According to rumors, the study rooms to the left of this room served as a religious school.
On the lowest (fifth) level, a cruciform church is reached via a flight of vertical stairs that begin between the third and fourth levels.
It appears that the substantial 55-meter (180-foot) ventilation shaft was used as a well. If the outside world was inaccessible, those in hiding could also get water from the shaft, as well as the villagers below.
According to the Turkish Department of Culture, the Phrygians may have first created caves in the soft volcanic rock of the Cappadocia region between the eighth and seventh centuries BC.
Archaeologists Discovered an Underground City That Was Home to Nearly 20,000 People