The first human activity on Ios dates to the Early Bronze Age; already at the end of this period the island is densely occupied. Several settlements are located on the headlands of the coast, Plakoto, Ag. Theodoti, Psathonisi, Plakes, Magganari, Skarkos. The latter is the largest of the island and one of the most significant and well preserved of the Cyclades during the 3rd millennium. During the Middle and Late Bronze Age a cemetery was in use on the site of the site Skarkos.
There is no sign of occupation during the Early Iron Age but by the Archaic period Ios was already a small city-state. Archaeological excavations have shown that the city was located on the hill of Kastro. There a wall reinforced an already naturally protected place. The site remained in use until the end of antiquity. In the remaining territory of the island numerous Hellenistic towers have been identified (Mersynia, Psaropyrgos). At Ellinika at Epano Kampos a particularly well preserved farmhouse of the Hellenistic period was found (part of the second floor can still be seen).From the Roman period there are some installations on the east coast of the island between Psathis and Ag. Theodotis and also a small settlement at Magazia north of the island.
Graindor, P. 1904. Fouilles d'Ios, BCH 28: 308-333.
Mantis, A. 2001. Υστεροαρχαϊκή επιτύμβια στήλη από την Ίο, Pantermalis, D., M. Tiverios & E. Voutyras (eds), Αγαλμα: Μελέτες για την αρχαία πλαστική προς τιμήν του Γιώργου Δεσπίνη, Θεσσαλονίκη, 67-78.
Marthari, M. E. 1999. Τo Αρχαιoλoγικό Μoυσείo της Ioυ: Σύvτoμη περιήγηση στις αρχαιότητες της Ioυ μέσω τωv εκθεμάτωv τoυ Μoυσείoυ, Αθήνα.