ERETRIA (mod. Aletria), an ancient coast town of Euboea about 15 m. S.E. of Chalcis, opposite to Oropus. Eretria, like its neighbour Chalcis (q.v.), founded colonies in the west and north of Greece. It also acquired dependencies among the Cyclades and had close alliance with Miletus. Defeated by Chalcis in the Lelantine War, it lost importance, and its interference in the Ionian revolt (498) brought upon it the vengeance of the Per sians, who destroyed it shortly before the battle of Marathon (490). The city was soon rebuilt, and was a member of both the Delian Leagues. The Athenians twice rescued it from the tyrants suborned by Philip of Macedon (354 and 341). Under Mace donian and Roman rule it fell into insignificance; for a short period under Mark Antony, it became a possession of Athens. Eretria was the birthplace of the tragedian Achaeus and of the "Megarian" philosopher Menedemus.
The modern village, which is sometimes called Nea Psara be cause the inhabitants of Psara, off Chios, were transferred there in 1821, is on unhealthy low-lying ground near the sea. The an cient site was excavated by the American School of Athens (189o-95). At the foot of the Acropolis lies the theatre, where only seven rows of seats remain, but much of the scena is pre served: beneath which there runs a tunnel, which has raised in teresting questions, the orchestra being at present about 12 ft. below that of the rooms in the scena. Near by are a temple of Dionysus, a large altar and a gymnasium. In 190o a temple of Apollo Daphnephoros was found. The wall of the Acropolis re mains to the height of eight courses; other walls, to north and south connect it with the harbour and mole.