Platamon Castle, dating back to the mid-Byzantine period (10th century), was built over the grounds of the ancient city of Heraklion and was restored by the Franks after 1204, the Byzantines during the 14th century, and the Turks. It is one of Greece’s best-preserved castles consisting of a defensive stone-wall and an octagonal fortress tower. Recent excavations have revealed a Byzantine church, dating between the 10th and the 11th century, houses belonging in the same period, an 18th century chapel, as well as storage spaces and a part of the wall from the Hellenistic period (2nd century B.C.) Controlling the passages of Olympus towards southern Greece, Platamon Castle was targeted by many foreign conquerors, but, also, by Greek revolutionists during 1821. It is open to visitors during the hours provided for archaeological monuments. During summer, it hosts many of the events organized within the context of the Olympus Festival.