The underground city of Kaymakler was built by Christians in the 7th century to escape persecution in Rome. There are 8 underground floors, more than 1,000 rooms, and the ventilation system is very good. Inside, the corridor room stairs are everywhere, and it is easy to get lost without signs. There are everything inside, there is a place to make wine, there is a place to store, there is a place to get water, there is a communal kitchen, etc. At that time, they had enough storage to live in it for half a year without coming out.