The Cyclades are a group of islands in the Aegean Sea, southeast of mainland Greece. The name refers to a circle: the islands lie around the sacred island of Delos, a UNESCO World Heritage Site. Volcanic landscapes shape Santorini and Milos. Naxos has ancient landmarks and sandy beaches, and Mykonos and Paros have lively harbour towns. Hiking paths cross smaller islands such as Folegandros and Anafi.