Cyclades (sĪˈklədēz) [key], Gr. Kikládhes [Gr., = circular], island group (1991 pop. 94,005), c.1,000 sq mi (2,590 sq km), SE Greece, a part of the Greek archipelago, in the Aegean Sea stretching SE from Attica. The name was originally used to indicate those islands forming a rough circle around Delos. The Cyclades include about 220 islands of which Tínos, Ándros, Mílos, Náxos, Kéa, Páros, Serifos, Ios, Kithnos, and Thíra are important. Ermoupolis, on Síros, is the chief town and administrative center of the group. Largely mountainous, with a dry and mild climate, the islands produce wine, fruit, wheat, olive oil, and tobacco. Iron, manganese, and sulfur are mined, and marble is quarried. Unplanned development and crowds of summer tourists have caused pollution and water shortages. The islands are noted for the Bronze Age artworks found there (see Cycladic art). In 1829 the Cyclades passed from the Ottoman Empire to Greece.