The Ambracian Gulf, also known as the Gulf of Arta or the Gulf of Actium, and in some official documents as the Amvrakikos Gulf , is a gulf of the Ionian Sea in northwestern Greece. About long and wide, it is one of the largest enclosed gulfs in Greece. The towns of Preveza, Amphilochia (formerly Karvassaras), and Vonitsa lie on its shores.