The Ihlara Valley is a canyon approximately 100m deep and 16km long which was formed by the Melendiz River thousands of years ago. Due to the valley's plentiful supply of water and hidden places, it was one of the first settlements of the first Christians escaping from Roman soldiers. The whole canyon is honeycombed with rock-cut underground dwellings and churches from the Byzantine period. It is believed that the valley housed more than four thousand dwellings and hundreds of cave churches decorated with frescoes. Around eighty thousand people once lived in Ihlara Valley.