English: Kaymakli Underground City in Cappadocia, Turkey. Christians fled the enemies and hid in this underground cities. A remarkable block of andesite with relief textures. Recently it was shown that this stone was used for cold-forming copper. The stone was hewn from an andesite layer within the complex. In order for it to be used in metallurgy, fifty-seven holes were carved into the stone. The technique was to put copper into each of the holes (about 10 centimetres (3.9 in) in diameter) and then to hammer the ore into place. The copper was probably mined between Aksaray and Nevsehir. This mine was also used by Asilikhoyuk, the oldest settlement within the Cappadocia Region.