It is the best known underground city in Cappadocia, where 36 underground cities exist. The city which is very large in size and has 8 floors, is assumed to have held 20.000. It was used especially during the enemy attacks. The floors are connected through narrow tunnels. The ventilation shafts, church, stone doors, storehouse, school, stable, cistern, the part for wine production, tombs, confession cell and the emergency exits are the interesting parts in Derinkuyu worth seeing.