The traces of the ancient Korakesion (or Koracesium) are today limited to the castle hill visible from afar with the presumably in Hellenistic time, so already in the 3rd century B.C. begun and later ever further developed fortress. In Seljuk period the Red Tower (Kızıl Kule) and a shipyard were built.

The fortress Alanya is situated on a rocky outcrop directly in the sea. Due to this location it was difficult to reach from the water as well as from the land and was therefore easy to defend for centuries. The Alanya rock was for a long time the basis for the settlement of early civilizations. They can be traced back to the 4th century BC. In the early Hellenistic period, the highest point of the rock nose was equipped with a defensive wall. In the following centuries it was further extended. The impressive fortification that we can visit today was completed by the Seljuks.

The "Red Tower" was built in 1226 at the behest of the Seljuk Sultan Alaeddin Keykubad I. It was built as a watch and defensive tower to protect the port and the fortress. It has the shape of an octagon, a diameter of 29 metres and a height of 33 metres. Despite its simple external appearance, its interior is extremely complex. It consists of 5 floors, which are different in their layout and design. For defence, the walls of the individual floors are provided with loopholes and some with pitch noses. Attackers were able to be fired upon from a battlemented wreath at the end.
From the tower the defenders had access to the battlements of the lower line of defence.