Built on a rocky cape, in the northern side of Kassiopi bay and above the picturesque settlement, Kassiopi Castle is the oldest castle in the island since it was built in the 1st century A.C. With the passing of the centuries, naturally it was destroyed and rebuilt many times and today only some of its parts can be found: its walls, towers, bastions, water reservoir, some cannons and of course the most imposing part of it, its restored central gate which, is surrounded by two towers with two floors. The perimeter of the castle is 1,073 km long and of rectangular shape with 19 strong towers of round or rectangular shape. The interior of the castle is a total area of 35,177 square meters and today it is full of olive trees.
Kassiopi Castle, during the Byzantine period, was a part of a defensive triangle which ensured the protection of the island, with Gardiki Castle in the south of the island and Aggelokastro in the north-western part. Its position in the north-eastern shores of Corfu, overseeing the northern strait of the island, gave the castle a high strategic importance.
Kassiopi Castle is accessible by the southeast through a narrow path that passes through the houses and yards of the dense settlement of Kassiopi.