The Minoa, Aegiali, Arkesini  were the three ancient cities that flourished on the island.
From the ruins of settlements and the important discoveries we can see the high level of culture of that area.

Ancient Minoa: The ruins of Ancient Minoa are located 3 km from the port of Katapola at top of the hill Mountoulia. Ruins include the Stadium, the Gymnasium of the ancient city and the temple of Dionysus.

Ancient Arkesini: At Katomeria, on the south side of the island at place “Kastri” are the remains of ancient Arkesini, the Tower of Agia Triada, a monument of the Hellenistic period built the 4th century and the prehistoric village of “Markiani”.

Ancient Aegiali or Melania: In the northeast coast, close to Tholaria in Vigla hill, the city of ancient Aegiali. There are remains of the ancient parts of the walls, bases of statues and tombs of Cycladic and Middle Cycladic period.

On a rock in the middle of the village of Chora, stands the Castle (Kastro), built in the 13th century by Jeremiah Gizi, part of which survives today. In Chora there is also the Venetian Tower of Gavras, a building of the 16th century. Also, Kato Lakos is a medieval cistern that watered the village.