According to the archaeological evidence to date it appears that during the Middle Bronze Age changes occur in the settlement pattern of the Aegean islands. These are visible in the reduction of the number of settlements and the concentration of a larger number of inhabitants in these. The changes result from the economic conditions that dominate in the Aegean during the end of the Early Bronze Age as well as from the new ones which are determined by the intense Minoan presence in the transit trade of the Aegean during the Middle Bronze Age.

Large, densely built and fortified towns, in which the most inhabitants of the island are sheltered are developed in the Cyclades for greater security. Phylakopi II extends on 18.000 square metres and includes building complexes of small houses built of rough carved stones. It has roads 1,5 metres wide which are orientated to the four directions, steps for passing from the lower to the higher levels of the settlement and most likely a wall built along the peninsula. Agia Irini on Keos (phases IV-V) includes a stone built wall fortified with hemispherical bastions while there is a building it its interior that is distinguished from the rest: the sanctuary of the community.

Only a few Early Bronze Age settlements with early urban features such as Mikro Vouni on Samothrace and Koukonisi on Lemnos are inhabited in the north Aegean. They are protected by stone fortification walls and their basic building unit is the long and narrow rectangular building with a small closed antechamber and a large main room (megaroid). The architectural continuity from the Early Bronze Age in the north Aegean islands which are often hit by earthquakes is verified by the dense building in building blocks similar to those of Thermi, the parallel roads (at least two) which run the settlement from north to south and are crossed vertically by other smaller ones, little public squares and wells (in Koukonisi).

The most important sites of the Middle Bronze Age.
Keos, Agia Irini. Plan of Middle Cycladic
and Late Cycladic buildings.