According to researchers, there are almost a thousand underground cities in Cappadocia. Among them, Derinkuyu is the deepest one. The excavation work in the underground city is still incomplete. Only eight levels of this ancient 18-story underground city are now open to the visitors. The city was built by carving soft rock. There are some huge tunnels all over the city connecting to some engraved caves. These caves could accommodate up to 10,000 people. Apart from these caves, there were some temples, food shops, wine stores and schools. There were also a few places to save the dead bodies. Until they were safely taken to the ground for their funeral obsequies, they were stored in the underground pits. There were about a hundred entrances hidden behind various bushes, walls and courtyards. Every entrance of this underground city was closed with a round stone-made door of about 5 feet wide and 500 kg.

These round stone doors protected the city from various dangers. Each level of this city was set up in such a way that each of them could be closed separately. There were some ventilation shafts for distributing air throughout the city. Each of them was 100 feet deep. There was a river flowing through the city. Many wells were built all over the city and they were connected to the river. Local inhabitants collected water from those wells. Derinkuyu was much more than a shelter or a residential place. It was like a fortress. When the city dwellers took shelter in the underground city under enemy attack, business or other activities in the area would not stop.

The city was a place for mass gatherings, grocery stores, huge food stalls and even the entire market. Weapons were always stored in the armory. And there were several ways to escape the city at times of danger.

Derinkuyu was different from any other underground city. It is hard to find an underground city as much self-sufficient as Derinkuyu. There was a barrel-shaped spacious room on the third floor of Derinkuyu. It was used as a religious education center. This education center had separate parts for each department.

A 180-foot wide trench was used as the main well of the city. People from both sides, on the ground or under the ground could use the well. There was a three-mile-long tunnel situated on the third floor of the city. This tunnel connects Derinkuyu to the nearby underground town of Kaymakli.

This passageway is currently closed due to landslides. Derinkuyu was also a protection against adverse weather. This city protected people from the heat or the intense cold and snow. When it was intense cold or hot on the top, the city below was in a comfortable state. As a result, animals or food items could be easily stored in this underground city.