The site was already inhabited in the 3rd-2nd millennia BC. At the beginning of the 8th century BC Eretria became one of the most important cities in Greece. The theater and the Temple of Dionysus were built in the 4th century BC. The western part of Eretria was occupied by residential houses of the 4th to the 2nd centuries BC. Underneath the Classical and Hellenistic houses archaeological excavations revealed remains of earlier periods (7th-5th centuries BC).