Feraklos Castle is a ruined medieval fortress, located on an 85 m-high hill overlooking the village of Charaki. It was originally built in the Byzantine era and captured by the Knights Hospitaller on 20 September 1306, being their first possession on the island that would become their base. By 1408 it was in ruins, and was repaired under the Grand Masters Giovanni Battista Orsini (1467–76) and Pierre d'Aubusson (1476–1503) as a stronghold to protect the area, and particularly watch over the anchorages at the Charaki and Agia Agathi beaches nearby.
After 1470, the Hospitallers abandoned all other fortifications on the island except for Feraklos, nearby Lindos, and the city of Rhodes, which in turn were further strengthened. A decree of 1474 prescribed that the Feraklos Castle was the place of refuge by the inhabitants of the villages of Malona, Salia, Katagros, Zinodotou, and Kaminari when there was danger.
The fort was captured by the Ottoman Empire in 1523 after a long siege, a few months after the capture of Rhodes. The Ottomans did not use the castle and it has since been abandoned.
The fortress has an irregular polygonal layout, with a wall perimeter of 680 m encompassing an area of 1,700 square meters. The northern and western portions date to Byzantine times, but the rest are additions or modifications by the Hospitallers. A single gate and two cylindrical towers survive in the southern portion of the walls, along with a cistern in the interior.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.