The castle, in its current form dating back to the Middle Ages, dates back to a fortress built by Rhodes in the second half of the 4th century BC. Its purpose was to protect the harbor used by the Rhodians as a naval base. An inscription from the 3rd or 2nd century BC has been preserved on the western corner of the tower. It mentions Sosicles of Amos, son of Nicagoras, overseer of Kastavi and the tower of Megisti, who is said to have dedicated this inscription to Hermes of the Propylaea. After the Knights of St. John conquered the island from the Byzantines in 1306, they built a massive 22 x 16 m tower with a sloping base on the site of the ancient fortress, using primarily stone from ancient buildings. Adjacent to the tower to the northeast was the castle courtyard with cisterns and other buildings, surrounded by a wall with two round towers and a bastion. These remaining remains are poorly preserved and difficult to access. The tower stump can be climbed via two metal ladders on the southeast side.
Source: Information board next to the fort