The castle of Saint Georgios is at the top of Peretata hill. The castle was built in the 12th century by Byzantine Emperors and became the capital of the island.It remained the capital of Kefalonia throughout the period of the Venetian rule till 1757. It occupies a total area of 16 acres, while the perimeter of the walls is 600 meters. It was named after the old chapel of Saint Georgios which was located at the top of the hill before the fortification. The outer walls of the castle which were constructed in 1504 are still preserved as well as some churches and other buildings of the same period. The ruins of a French bridge that connected the ramparts, inside are also visible. The church of Evangelistria is also impressive. It was built in 1580 as the marble inscription inside the church suggests. It was the Metropolitan Church of the medieval capital of Kefalonia till Argostoli became the capital in 1757. Inside the Castle, there is the church Evangelistria which is a single-aisled basilica with a wood-carved iconostasis. The bell tower of the church is also preserved. Lastly, inside the church, there is a collection of post-Byzantine icons found in the other churches of the castle. In the courtyard of the fortress, there are also the ruins of the Catholic church of Saint Nicholas.