The plateau of Antalya is made of travertine. This plateau was formed by limestone that was dissolved and carried away by water. Under this formation there are various fresh water springs which flow into the sea. Suluin cavern in Kirkgoz was filled with this kind of material, but in the olden times it was an underwater cavern. In 1995 the depth of this cavern was found to be 83 meters. When continued down from the canals about 45 meters, a gigantic hole is reached. The walls of this empty space are covered with stalactite and stalagmites, travertine pools and other formations. A large number of side canals opening onto this space were found after several dives.