The Castle of St. George was built in the 12th century. The castle has a polygonal shape, occupies a total area of ​​16 hectares and the perimeter of its walls is 600 meters. The old chapel of St. George, which was on the top of the hill before its fortification, gave it his name.

In 1500 the Castle was taken by the Venetians and the Spaniards who recaptured the island after a short Ottoman occupation of 16 years. Its Venetian exterior walls built in 1504 on the ruins of the Byzantines are preserved in good condition today, as well as the buildings and the remnants of a wooden bridge in the interior. There are sources reporting the existence of an underground tunnel connecting Castro to Argostoli, which has not been proven by archaeological research. The settlement of the Castle was developed both internally with buildings related to administration, temples, warehouses, barracks, hospitals, prisons, tanks and houses of nobles (borgo) and externally (exobourgos), some of which exist and are inhabited to this day. However, in the late 16th century, with the retreat of piracy, the Castle lost its defensive significance, so in 1757 the capital of Kefalonia was moved to  Argostoli.

On the hill of the Castle we can see the metropolitan church of Evangelistria, built in 1580. It is a one-aisled basilica with the architectural elements of the Ionian baroque. We can admire its wood-carved icon screen and remarkable post-Byzantine icons from the ruined other temples of the Castle.

The Castle today is a picturesque settlement that offers the visitor an unobstructed view of the whole area of ​​Leivathos and the west while also enjoying its food or drink in a quiet place just a stone’s throw from Argostoli.