According to tradition, Donoussa was the island where Dionyssus hid Ariadne, after he stole her from Theseus. Excavations on the island indicate that it has been inhabited ever since the Geometric Era. There are no other clues to the island's history, until the Roman Era when it served as a land of exile, while, in the Middle Ages, it provided refuge to the pirates. The island of Iraklia was inhabited in ancient times. There is no information regarding the island's history, as no excavation has been conducted here. Like Donoussa, Iraklia provided refuge to pirates in the Middle Ages, while the ruins of the castle in the south-east indicate that the island was inhabited during the Venetian Rule. For a period of time, the island was owned by the Monastery of Panagia Hozoviotissa, in Amorgos. The deserted island of Keros is the one of the greatest historic interest. In ancient years, it was called "Keria". According to archaeological findings, it was a vital centre of the Cycladean Civilization. There is no extensive information regarding the history of Koufonissia. Excavations brought to light findings of the Cycladean Civilization. The islands served as pirate headquarters, during the Turkish Occupation. According to historic sources, Schinoussa was inhabited in the Pre-historic Era and during the Venetian Rule, while it also served as pirate headquarters during the Turkish Occupation. Like Iraklia, Schinoussa belonged to the Monastery of Panagia Hozoviotissa.