The first traces of the Ancient Cycladic culture on this group of islands date from about 3.000 B.C.

The islands' mild climate, combined with its plentiful metal ores and its marble, all helped to develop this culture, which is among the oldest of Greece. Inhabitants of the Cyclades were masters in sailing and arts. They were great travellers and established commercial links with nearby lands.

The Ancient Cycladic culture is divided into 3 periods.The most important of them is the 2nd, called the culture of Syros-Keros (2800-2200 B.C.), when the development of Syros reached its peak.

The archaeologist Christos Tsoundas was responsible for the major part of archaeological work on the island.

The most significant settlement on Syros of this period was situated in the region of Chalandriani in the northern part of the island. Testimonies to the life of the island's early inhabitants, such as works of art and innumerable tombs, were uncovered. They led to the conclusion that this settlement was of great importance. Built on top of a hill, it was surrounded by a fortified wall, featuring numerous towers.

Archaeologic works in Chalandriani brought to light an important number of graves of this period. All of them, in the form of a circle or a square, are built of small stones and covered with slabs. Countless items from everyday life, such as utensils, statuettes, jewelry, weapons and tools were discovered as well. Remains of other settlements were found in different parts of Syros: at "Agia Thekla" in Chroussa, in Chondra at a site called Koskinos, near to Vari, which is supposed to be the oldest settlement of Syros. Many objects fashioned of volcanic glass were found there.

The people of the Cyclades were excellent artists. They created objects that were both useful and decorative. But the greatest contribution to their art consists of the marble idols found on many islands of the Cyclades. These idols usually represent women with bent legs, hands crossed on the breast and the head in the shape of a lyre.

Other characteristic items of the period are objects in the shape of a frying pan with a peculiar decoration of spirals and stylised ships. They may have been used for religious purposes or perhaps as a mirror - the hollow side would be filled with water in which one's face would be reflected.