Set 65 km from Kayseri, the Erdemli (Erdemesin) Valley (Erdemli Vadisi) was an important settlement during the Byzantine period. The district of Yeşilhisar, to which the valley is connected, was called “Kyzistra” during the Byzantine period. Erdemli Valley is approximately one kilometre long and contains a palace structure and eight rock churches (Church Mosque, H. Eustathios Church, Double Apsed Burial Chapel, H. Nikolaos Church, H. Michael Church, Twelve Apostles Church, Forty Martir Church, Single-Nave Church).