Apart from the impressive stone pillar forest caves, there are also many underground cave cities in Cappadochia, Turkey. These underground cities, which existed 400 B.C., have orderly passages, ventilation holes, domestic water and drainage systems. In addition, there are caves with different functions, such as churches, classrooms, bedrooms, kitchens and warehouses. The huge underground city can accommodate 10,000 people living at the same time. Live. In Cappadochia, 37 underground cities have been opened to the outside world. Conservatively, it is estimated that at least more than 100 underground cities have not yet been excavated. The total size of these underground shelters may remain a mystery.