Cappadocia has one of the most interesting and spectacular landscapes in the world. About three millions years ago the volcanoes of Mt. Erciyes and Mt. Hasan covered the surrounding plateau with volcanic tuff as a result of their violent eruptions. The natural effects of wind, water and rain eroded this area into a spectacular, surrealist landscape of rock caves, capped pinnacles and fretted ravines in colors ranging from warm tones of red and gold to cool tones of green and gray. Dating back to 4000 BC; the earliest people used to live in Goreme, known as Cappadocia, in dwellings dug into the rock. Christianity came to the region, and chapels, churches and monasteries were constructed in the rocks. At Derinkuyu, Mazi and Kaymakli, cities were developed underground in order to hide from raiders. There is another underground city -Ozkonak- which is also open to public. They are really amazing to visit, and give a sense of the way people must have felt while living underground.