Ionian Islands (region) party. Ionian Islands (region) The Ionian Islands Region (, , ) is one of the thirteen administrative regions of Greece. The administrative region does not include all of the Ionian Islands; the island of Kythera, which historically was part of the island group, was separated and integrated to the (far away) Attica Region. The population of the Ionian Islands in 2011 was 207,855, decreased by 1,50% compared to the population in 2001. Nevertheless, the region remains the third by population density with 90.1/km² nationwide, well above the national of 81.96/km². The most populous of the major islands is Corfu with
Ionian Sea Sea, and from Piraeus westward. Calypso Deep, the deepest point in the Mediterranean at , is located in the Ionian Sea, at . The sea is one of the most seismically active areas in the world. The name "Ionian" comes from the Greek language . Its etymology is unknown. Ancient Greek writers, especially Aeschylus, linked it to the myth of Io. In Ancient Greek the adjective "Ionios" () was used as an epithet for the sea because Io swam across it. According to the "Oxford Classical Dictionary", the name may derive from Ionians who sailed to the West. There were