Aigosthena

The ancient fortress of Aigosthena stands in West Attica, near the coastal village of Porto Germeno and about 450 metres from the sea. It is generally regarded as the best-preserved ancient fort in Greece, and it remained in use into the early Byzantine period, perhaps later. In classical times the settlement belonged to Megara, and the fortress was probably built around 343 BC, when the Athenians helped Megara against the threat of Thebes; an Athenian guard manned the walls. The acropolis occupies the hilltop over an area of 190 by 80 metres, with the eastern walls still standing high, complete with four towers and a small gate. The most striking feature is the square southeastern tower, 20 metres tall with sides of 8.9 metres. A fortified wall once linked the acropolis to the harbour, though only traces of its northern side remain. Byzantine relics include a 5th-century basilica church, and there are also ruins of a post-Byzantine monastery.