The fortified settlement of Kastro (Castle) lies 4 km east of Apollonia. Ancient ruins of an 8th-7th century BC settlement and a 6th century BC fortification wall on its north-west side indicate that the area was already settled from prehistoric times. Up until 1836, it was the island's capital and served as a castle against pirate raids. Its houses and imposing mansions remind one of its glorious history and transport one to the medieval and Venetian rule eras. Inside the settlement, there are notable churches, like the 17th century Agia Eleoussa with its valuable icons and a noteworthy collection of ecclesiastical relics, the 16th century Agios Nicholas, Agia Catherine, Theoskepasti, Agii Saranta, and Agios Dimitrios. Lastly, in the Catholic church of St Anthony, there is a small but interesting archaeological collection