Dokos is a small rocky island located between Ermioni and Hydra. The island, which in ancient times was called Aperopia was already inhabited in the Neolithic era (4th millennium BC) and showed particular growth since the 13th century. BC, with the establishment of settlements.
Today in Doko are preserved ruins Early Helladic, Late Helladic and Hellenistic settlements and remains of Hellenistic and Byzantine monuments.
Also in the marine region of the island was discovered in 1975 and excavated systematically from 1989 to 1992 the oldest shipwreck in the world. The wreck, found in a depth of 15-30 meters, is placed in the second Early Helladic period (2700-2200 BC) and carried ceramics load.
On the east side there are the remains of a large Byzantine-Venetian castle. During the Revolution of 1821 it was used by the fleet of Hydra as a winter anchorage.