Kythnos (Greek: Κύθνος) is a Greek island and municipality in the Western Cyclades between Kea and Serifos. It is 56 nautical miles (104 km) from the Athenian harbor of Piraeus. The municipality Kythnos is 100.187 km2 (38.68 sq mi) in area and has a coastline of about 100 km (62 mi). It has more than 70 beaches, many of which are still inaccessible by road. Of particular note is the crescent-shaped isthmus of fine sand at Kolona.
The island has two significant settlements, the village of Messaria or Kythnos (pop. 561 in 2011 census), known locally as Chora, and the village of Dryopis or Dryopida (pop. 325), also known as Chorio. Both villages are notable for their winding and often stepped streets, too narrow for vehicular traffic. The villages are very picturesque but in different architectural styles. Chora has the more-typical flat roofs of the Cyclades, while Dryopida’s rooftops are slanted and tiled. Chora is also notable for its large Greek Orthodox Church.
There is also a growing coastal settlement called Kanala on the east side of the island, and many of the larger beaches are settled by a handful of residents. Aghios Dimitrios, at the southern tip of the island, is a mostly modern settlement, with small vacation houses dotting the hillside above a wide beach that is dotted with sea daffodils. On the northeast end of the island lies Loutra (pop. 81), a village famous for its thermal springs, which are said to have curative properties. Although the large tourist hotel there has been closed for several years, the bathhouse is still functioning and visitors may soak in its marble tubs for a modest fee.
The port town is called Merichas (pop. 369), its population significantly fluctuating during the year. Before the 1970s, there were no year-round residents in recent history; a Greek fisherman named Manolas Psaras and his wife Foto were the first to live in the port year-round. Today, there is a growing year-round population, and, especially during the peak of the summer tourist season, the town becomes quite busy. Many residents of the port speak at least some English, the most popular second language. Merihas is connected to Piraeus and to Lavrion by ferry boat, and the ride takes one to four hours, depending on the speed of the ship and the weather. Construction of a new mole began in 2005 to accommodate larger ferryboats and was completed in 2008. Kythnos was until recently considered to be one of the last Cycladic islands unaffected by the impact of tourism, but this is inexorably changing. Still, the island has not yet been overdeveloped, and in the more remote areas of the villages, traditional ways live on relatively unchanged.