Adriatic Sea southeast, the Adriatic Sea connects to the Ionian Sea at the wide Strait of Otranto. The International Hydrographic Organization (IHO) defines the boundary between the Adriatic and the Ionian seas as a line running from the Butrinto River's mouth (latitude 39°44'N) in Albania to the Karagol Cape in Corfu, through this island to the Kephali Cape (these two capes are in latitude 39°45'N), and on to the Santa Maria di Leuca Cape (latitude 39°48'N). It extends from the northwest to the southeast and is wide. It covers and has a volume of . The Adriatic extends northwest from 40° to
Ionian Islands are found because Io swam across it. Latin transliteration, as well as Modern Greek pronunciation, may suggest that the Ionian Sea and Islands are somehow related to Ionia, an Anatolian region; in fact the Ionian Sea and Ionian Islands are spelled in Greek with an omicron (Ιόνια), whereas Ionia has an omega (Ιωνία), reflecting a classical difference in pronunciation. In Modern Greek omicron and omega represent the same sound, but the two words are still distinguished by stress: the western "Ionia" is accented on the antepenult (), and the eastern on the penult (). In English, the adjective relating to