Cythera is an island in Greece, once part of the Ionian Islands. It lies opposite the south-eastern tip of the Peloponnese peninsula. It is administratively part of the Islands regional unit, which is part of the Attica region (although at large distance from Attica itself), Greece.
For many centuries, while naval travel was the only means for transportation, the island possessed a strategic location. Since ancient times, until the mid 19th century, Kythira had been a crossroads of merchants, sailors, and conquerors. As such, it has had a long and varied history and has been influenced by many civilisations and cultures. This is reflected in its architecture (a blend of traditional, Aegean and Venetian elements), as well as the traditions and customs, influenced by centuries of coexistence of the Greek, Venetian, Ottoman and British civilisations as well as its numerous visitors.
Cythera and the nearby island of Antikythera were separate municipalities until they were merged at the 2011 local government reform; the two islands are now municipal units. The province of Cythera (Greek: Επαρχία Κυθήρων) was one of the provinces of the Piraeus Prefecture. It had the same territory as the present municipality Cythera. It was abolished in 2006.
Cythera has a land area of 279.593 square kilometres (107.95 sq mi); it is located at the southwestern exit from the Aegean Sea, behind Cape Malea. The rugged terrain is a result of prevailing winds from the surrounding seas which have shaped its shores into steep rocky cliffs with deep bays. The island has many beaches, of various composition and size; only half of them can be reached by road through the mountainous terrain of the island.
Cythera is close to the Hellenic arc plate boundary zone, and thus highly prone to earthquakes. Many earthquakes in recorded history have had their epicentres near or on the island. Probably the largest in recent times is the 1903 earthquake near at the village of Mitata, that caused significant damage as well as limited loss of life. It has had two major earthquakes in the 21st century: that of November 5, 2004, measuring between 5.6 and 5.8 on the Richter scale and the earthquake of January 8, 2006, measuring 6.9 on the Richter scale. The epicenter of the latter was in the sea about 20 km (12 mi) to the east of Kythira, with a focus at a depth of approximately 70 km (43 mi). Many buildings were damaged, particularly old ones, mostly in the village of Mitata, but with no loss of life. It was felt as far as Italy, Egypt, Malta and Jordan.
The Kythirian Straits, formed by the southeastern peninsula of the Peloponnese and the islands of Elafonissos and Cythera represent one of the most dangerous navigational hazards in the Mediterranean. Most sea-traffic from Athens, Istanbul, and the Black Sea to the central and western Mediterranean passes through the straits and are often subject to strong winds and shipwreck on Cape Malea.