The concept of underground cities in Cappadocia began in the Bronze Age of the Hittite period, but it is also famous for its early Byzantine history (6th-7th centuries) when the Christians living there began to live underground for long periods to escape the Persian invaders. Kaymakli or the Underground Elven City is the largest vivid example of ancient Cappadocia, with a maze of rooms connected through eight-level tunnels. Dealing with the network of tunnels clad underground is a wonderful experience.