The old fortress (in Greek Paleo Frurio) is an old Venetian fortress built on an artificial island with defensive structures around the perimeter, although some sections, especially on the eastern side, are gradually falling apart and falling into the sea. However, the interior has been restored and is used for cultural events such as concerts and sound and light shows, where historical scenes are played out using sound and light special effects. These events take place in the heart of ancient fortifications with the Ionian Sea in the background.

The highest point in the center of the citadel rises like a huge obelisk with a military vantage point with a huge cross on top. At its foot is the church of St. George in the classical style with the addition of six Doric columns, in contrast to the Byzantine architectural style of the Orthodox churches of the main part of Greece, built during the British rule and the imposition of the Anglican Church.