Sifnos is an island municipality in the Cyclades island group in Greece. The main town, near the center, is known as Apollonia, home of the island's folklore museum and library. The town's name is thought to come from an ancient temple of Apollo. The second-largest town is Artemonas, thought to be named after an ancient temple of Apollo's sister-goddess Artemis. The village of Kastro, built on top of a high cliff on the island's northwestern shore on the site of the ancient city of Sifnos, today has extensive medieval remains and is the location of the island's archeological museum. The port settlement, on the west coast of the island is known as Kamares. Sifnos lies in the Cyclades between Serifos and Milos, west of Delos and Paros, about 130 km from Piraeus. It has an area of 74 km² and a shoreline of 70 km, with a permanent population of 2442. Sifnos is known today as a holiday destination, because of its natural beauty and the bustling or secret beaches.