Syros has been settled for first time during the 3rd millennium BC. Syros has known a period of prosperity in Hellenistic and Roman era as it is proved by the coins that were found in excavations that took place mainly at the 19th century. In the 13th century, Syros devolves to the Venetians, who found the settlement of Ano Syra, on one of the two hills of current Ermoupoli. Since then, Ano Syra was distinguished as one of the Roman Catholic settlements of Greece. During the Greek Revolution Syros gave asylum to the refugees from other parts of Greece who settled on the foothills of Ano Syra, near the harbour, where they founded the city of Ermoupoli.
The Town Hall of Syros has been designed by the architect Ernest Ciller and due to this special architecture it has been characterized as National Historical Landmark and is a protected settlement. In the same region there are the Intellectual Centre, the Municipal Library and the Municipal Theatre Apollo which is considered to be a copy in smaller scale of the Italian “La Skala” of Milan. Posidonia, is another name of Delagratsia, that has been a holiday resort for the sovereigns of the 18th and 19th century, where mansions and neoclassical houses were built. Posidonia is still a very popular summer resort with many hotels.