Plaka (Greek: Πλάκα) is a village in the northeasternmost part of the island of Lemnos, Greece.

Some believe that it is the Ermaion lepas of the ancient, through which was transmitted with fire the news of the sack of Troy to Argos and Mycenae.

The cape was mentioned by older travellers under different names: Palaqa burnu (Piri Reis 1521), Blava (Belon 1548, Dapper 1688, Choiseul-Gouffier 1788, Lacroix 1858) and Plaka (Conze 1858, Tozer 1859, De Launay 1894, Hauttecoeur 1903, Fredrich 1904).

The currently deserted medieval settlement of Axia (Αξιά) or Naxa (Νάξα) is situated between the villages of Panagia and Plaka.

Several decades ago expatriates from the USA built a new chapel of Agios Charalambos and a block of cells for the visitors.

A 1355 paper under the census of the Great Lavra Monastery in Athos mentioned that there was a fortified settlement known as Kastrin (Καστρίν) in the area around Plaka.

In 1521, the Turkish admiral Piri Reis named it "Burun Hisãr", (literally the Castle of the Cape).

In the southern part of the Vriokastro peninsula at a distance of 800 m from the coast and east of the shoal Vina, ruins of a sunken ancient city were found, examined by professor Moutsopoulos in 1969.

He spotted a block of buildings with walls up to 2 meters, monolith lintels and stone paved roads.

Obviously in the past there was land to the east of the Plaka peninsula, which was either united with the mainland by a narrow panhandle or was a separate island.

On this stretch of land was probably located the city of Chryse of the Homeric period—sunk in 197 BC—, its ruins now visible in the depths of the sea.

This name was given by the bishop Joachim III, referring to the interest (συμφέρον) of its residents who fled from Agios Ypatios.

Although isolated in an extremity of Lemnos, the village saw good economical development, mainly based on agriculture (cereals, cotton, livestock, honey), fishing and sponge diving.