Cesme Archaeological Museum; built by the Genoese during the XIV. C. and renovated from 1508 / 1509 by the Ottoman Sultan Bayezid II, Cesme Castle's destroyed by the Venetians in the XVII. c. only to be reconstructed in the eighteenth century. The original construction of the castle was next to the sea, as a result of the landfill över the centuries, the castle is now found in its present position several metres from the shore. With its Ottoman architecture, the castle attracts attention, look out especially for the castle's south gate which is particularly magnificent. During the time of Sultan Bayezid II, the renowned architect Ahmetoglu Mehmet built the castle on a rectangular plan of around 11.700 m². The castle was divided into an inner and outer section. Three sides of the castle were surrounded by a moat, the IV. side had no need of a moat as it was flanked by the sea at the time of construction. The outer castle, as well as being surrounded by a moat, also had the protection of two ramparts. The inner castle was situated within a third rampart with two doors for entering and exiting to a central courtyard. Ýn the west wing of the castle were six towers two round towers positioned outside the castle, two rectangular towers inside and two further round towers inside to the east. The inner castle was positioned on an east, west axis and had two courtyards linked by a gate.
Cesme Castle's 50 sections which for many years were used by the Ottomans as both a military base and as a secure place to carry out maritime trade from the nearby port.
Today, the artefats excavated from the ancient site of Erythrai are on display inside the castle's Archaeological Museum, and the castle stands as a proud monument to its past.