The Ionian Sea (Greek: Ιόνιο Πέλαγος, Italian: Mar Ionio, Albanian: Deti Jon) is an elongated embayment of the Mediterranean Sea, south of the Adriatic Sea. It is bounded by southern Italy including Calabria, Sicily, and the Salento peninsula to the west, southern Albania to the north, and the west coast of Greece.
All major islands in the sea belong to Greece. They are collectively referred to as the Ionian Islands, the major ones being Corfu, Zakynthos, Kephalonia, Ithaca, and Lefkada. There are ferry routes between Patras and Igoumenitsa, Greece, and Brindisi and Ancona, Italy, that cross the east and north of the Ionian Sea, and from Piraeus westward. Calypso Deep, the deepest point in the Mediterranean Sea at −5,267 meters (−17,280 feet), is located in the Ionian Sea, at 36°34′N 21°8′E. The sea is one of the most seismically active areas in the world.