Ancient Poliochni, on the east coast of Lemnos, occupies an elongated rise protected by the cove of Vroskopos and flanked by the rivers Avlaki to the west and Stenoudiako to the north. Poliochni prospered greatly thanks to its commercial contacts with the Northeast Aegean islands, the coast of Asia Minor, the Greek mainland, and the Cyclades. It is considered one of the large early urban centres of the Early Bronze Age and the first city in Europe with a basic social and civic structure.

Current archaeological research places Lemnos in the cultural realm of the Northeast Aegean, together with Troy, Thermi on Lesbos, Emporio on Chios, and the Heraeon on Samos. Lemnos was a hub for commerce in metals and for maritime trade in general, strategically positioned between western Asia Minor and the Aegean. Poliochni was established on a site that offered safe mooring, plentiful supplies of drinking water, and fertile land. The site was inhabited from approximately the middle of the fifth millennium until the end of the second millennium BC.

Each of Poliochni's architectural phases is represented by a different colour. In the Neolithic period (Black Period, 3700-3200 BC) a small village of oval huts occupied the hill's centre. In the Early Bronze Age (Blue to Yellow Periods) the settlement saw great development. The Blue Period settlement (3200-2700 BC), which was probably established before Troy I, covered the entire cape and had a population of approximately 800 to 1,000. The settlement continued to grow in the Green Period, reaching a population of almost 1,500. In the subsequent Red Period (2400-2200 BC), however, the population decreased, and the city was completely abandoned in the Yellow Period (2200-2100 BC), after a devastating earthquake hit the region at the end of the third millennium.

Strong retaining walls, an enceinte, public buildings, squares, paved roads with water drains, wells, mansions, and smaller stone-built houses were constructed during the town's floruit. New shapes developed in pottery: the stemmed fruit-bowl of the Black Period, the tripod cooking pot of the Blue Period, and the depas cup of the Yellow Period, also common in the later strata of Troy II. The people of Poliochni were involved in agriculture, fishing, textile production, and the manufacture of stone tools and weapons. There are indications of metalworking and of the use of the lost wax technique as early as the Green Period, and of an increase in commercial activities during the Red Period. Life at Poliochni resumed in the Gray and Purple Periods, with limited, however, resources, and the hill was abandoned toward the end of the Late Bronze Age until the Middle Ages.

Excavations at Poliochni by the Italian School of Archaeology at Athens began in the 1930s. A. Della Seta, the School's director, and his students excavated almost two thirds of the settlement in 1931-1936. Further research was carried out in 1951-1956 by L. Bernabo Brea, who also published the excavation results, and new excavations began 1986 under S. Tine, with the aim of restoring the buildings and re-examining certain facts by conducting trial excavations.

Several other settlements developed on Lemnos at the same time as Poliochni. Recent rescue excavations at Myrina, on the island's southwest coast, by the Twentieth Ephorate of Prehistoric and Classical Antiquities, revealed two more settlements, one on the hill of the Weather Station and another at Richa Nera. The joint excavations of the Greek Archaeological Service and the Academy of Athens carried out under Christos Boulotis since 1992 revealed important remains of the Red Period at Koukkonisi, in the protected cove of Moudros. The settlements at Vriokastro, Trochalia, Mikro Kastelli, and Axia were probably less important.