Kekova, the largest Turkish Island in the Mediterranean Sea, is across from Üçağız on the mainland. There are the aims of a sunken city along the coastline facing the mainland. The island has 19 km of coastline. The sunken remains of the port and some buildings can be seen clearly. It is assumed that the ancient city was sunk by an earthquake in the 3rd century B.C.
The island, where there is now a ban on settling, was inhabited by the Greeks until the end of the last century. The remnants of a chapel and some buildings in the inlet of Tersane, in the west of the island are of particular interest. Boat trips also include the Blue cave, which is fascinating because of the harmony of different colours appearing because of the refraction and reflection of sun light.