Tokmar Kalesi, located about 30 km before Seleucia ad Calycadnum (Silifke), can only be dated to the end of the 12th century on the basis of architectural comparisons and is therefore of Armenian origin. Yilankale Castle in flat Cilicia may have served as a model. Probably it is identical with the castle Norpert (new castle), which is mentioned in the years 1199 and 1210 as property of a Sevasdios Heri. In 1210 the Armenian king Leon II handed over the fortress under the name Castellum Novum together with the town and citadel of Silifke to the Johanniter. In return, he received armed support from 400 knights in the fight against the Seljuks, as well as an annual payment of an undisclosed 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 steep mountain spur, the Kale Tepes, which slopes down to the sea. To the north, the mountain spur connects as a saddle to the Akçali Daglari mountain range. The castle is mentioned in the Portolan Rizo of 1490 as a landmark named "lo chastel chamandrachi" (presumably castle to the port).

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 located in a shallow bay opposite the castle, near the place today called Barbaros Köyü and is visible from Tokmar Kalesi. Judging by the types of tombs found in the western necropolis of today's beach, Palaiai was a Roman city whose ruins have sunk into the water.

The surrounding wall of the castle, which encloses an area of 50 x 70 metres, consists of polygonal quarry stone masonry and follows the conditions of the terrain. Four semicircular bastions have been preserved on the north side, which is not protected by the landscape. Large parts of the 1.5 metre thick walls in between have collapsed. Like the bastions, they are double-skinned with ashlars made of limestone. The entire gate front with the main gate no longer exists. Inside, the remains of a residential building can be seen, only the foundations of other buildings have survived.