Tokmar Kalesi, a good 30 km off Seleucia ad Calycadnum (Silifke), can only be dated to the end of the 12th century on the basis of architectural comparisons and is thus of Armenian origin. The Yilankale castle in Cilicia may have served as a model.

It is probably identical to Norpert Castle (New Castle), which was mentioned in 1199 and 1210 as the property of a Sevasdios Heri. In 1210 the Armenian king Leon II. handed over the fortress together with the town and citadel of Silifke to the Johanniter under the name Castellum Novum. In return, he received armed support from 400 knights in the fight against the Seljuks, as well as an annual payment of an unconfirmed amount. While Silifke Kalesi was returned to the Armenians in 1226, nothing is known about the fate of Tokmar Kalesi.

The castle is situated at an altitude of about 400 metres on a steeply sloping mountain spur, the Kale Tepes. To the north, the mountain spur joins the Akçali Daglari mountain range as a saddle. The castle is mentioned in the Portolan Rizo of 1490 as a landmark called "lo chastel chamandrachi" (probably castle to the harbour).

In the map of Asia Minor by Richard Kiepert, (German geographer and cartographer, † 1915 in Berlin) it is registered as Burg Palaea, which indicates that it belonged to the ancient port of Palaiai four kilometres to the east. This was situated in a shallow bay opposite the castle, near the place today called Barbaros Köyü and can be seen from Tokmar Kalesi. According to the grave types found in the west of today's beach, Palaiai was a Roman city whose ruins sank into the water.

The surrounding wall of the castle, which encloses an area of 50 x 70 metres, is made of polygonal quarry stone masonry and follows the conditions of the terrain. On the north side, unprotected by the landscape, four semicircular bastions have survived; large parts of the 1.5-metre thick walls in between have collapsed. Like the bastions, they are built in two shells with ashlars of limestone. The entire gate front with the main gate is no longer available. Inside, remains of a residential building can be seen, only foundations of other buildings have survived.