The Cyclades (/ˈsɪklədiːz/; Greek:Κυκλάδες, [cikˈlaðes]) are an island group in the Aegean Sea, southeast of mainland Greece and a former administrative prefecture of Greece. They are one of the island groups which constitute the Aegean archipelago. The name refers to the islands around (κυκλάς) the sacred island of Delos. The Cyclades is where the native Greek breed of cat (the Aegean cat) originated.