Gardiki Castle is a 13th-century Byzantine castle on the southwestern coast of Corfu and the only surviving medieval fortress on the southern part of the island. It was built by a ruler of the Despotate of Epirus, and was one of three castles which defended the island before the Venetian era (1401–1797). The three castles formed a defensive triangle, with Gardiki guarding the island's south, Kassiopi Castle the northeast and Angelokastro the northwest
The castle is located on a low hill near the village of Agios Matthaios which is situated at a higher elevation. The ruler responsible for the construction of the castle is not known, but it is assumed that it was built either by Michael I Komnenos or his son Michael II Komnenos, rulers of the Despotate of Epirus. Immediately to the south of the castle lies Korissia Lake which is separated from the sea by a narrow strip of land.
Remains from the upper Paleolithic era, dating from 20,000 BC., when Corfu was still united to the mainland region of Epirus, were found on the site of the castle at the rock shelter of Grava Gardikiou, including hunter-gatherer stone tools and animal bones, which have since been removed and are exhibited at the Archaeological Museum of Corfu.
The walls of Gardiki Castle form an octagon and the structure features eight strong towers decorated by rows of tiles. There are elements from an ancient structure which have been incorporated into the construction of the castle. The ancient structure was probably a fountain-house.
The eight towers are square in shape and the outline of the octagonal structure is almost elliptical. At the top of the southern tower there are traces of a chapel with remnants of religious frescoes of portraits of saints. Although in a state of disrepair, the towers still retain their full height. The castle entrance is preserved but the interior is in a state of ruin.
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.