One of ancient Lemnos’ two city-states, Hephaistia’s prosperity lasted from the 7^th to the 1^st century BC according to excavations and historical records. The city-state was the center of the ancient Greek religion, as the city was named after its protector the god Hephaestus. Coins discovered at the site, one of which depicts a burning torch on one side, suggest that “Hephaistia” festivals were performed in honor of Hephaestus.

Established by the Pelasgians on a peninsula that allowed them easy control over the two naturally created harbours, Hephaistia was a major port.

Numerous tombs with pottery have been discovered, the oldest of which dates to the first part of the 5^th century, with additional tombs dating back to Roman times. Among the Greek structures is the theater constructed during the Hellenistic era using Roman materials. The temples and houses, among other structures excavated, attest to the prominence of this city throughout the Byzantine period.

Two factors contributed to the downfall and eventual abandonment of Hephaistia: first, the loss of the port as a result of alluvial deposits following the frequent intense rainfall, and second, the prevalence of Christianity in the 2^nd to 3^rd century. Unable to practice their religion freely, the Christians sought a new base in Kotsino, the success of which accelerated Hephaistias’ demise.