The fortified settlement on Lygia peninsula, consisting of three consecutive castles, occupies a total area of about 58 hectares.

The eastern and smaller in size -about 1,2 hectares- castle A occupies the isolated hill which controls the entrance of the peninsula from the mainland. Better preserved are south and east side of the isodomic walls protected by nine towers, four semicircular and five rectangular. The castle's main arched gate is on the east side. Some traces of other gates are found in the south and the west side of the fortification, parts of which seem to have been violently destructed.

Castle B occupies the main hill of the peninsula and its size is estimated at about 20 hectares. It is connected with the eastern hill through a low neck, on which there are few traces of fortification walls. The conservation status of the fortification is fragmentary. The best preserved part is located to the southeast, where there are some remains of two semicircular towers.

Of Castle C on the west (36 hectares in size) only a few traces are to be seen.