Potiri Castle is located in Avlonari and is a typical Byzantine castle with a church devoted to Virgin Mary, dating back to the era of the Franks. This historic castle was operating from the Byzantine era until the Ottoman occupation. Access is not easy; you have to make a twenty minutes ascent on the path of mountain Oktonia. However, the view of Eviakos and the Aegean Sea is amazing. It’s definitely worth a visit.