Adriatic Sea Adriatic Sea The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to the northwest and the Po Valley. The countries with coasts on the Adriatic are Albania, Bosnia and Herzegovina, Croatia, Italy, Montenegro and Slovenia. The Adriatic contains over 1,300 islands, mostly located along its eastern, Croatian coast. It is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of
Ligurian Sea part. The sea receives the Arno River from the east and many other rivers that originate in the Apennines. The ports of Genoa, La Spezia, and Livorno are on its rocky coast. It reaches a maximum depth of more than northwest of Corsica. The International Hydrographic Organization defines the limits of the Ligurian Sea as follows: "On the Southwest." A line joining Cape Corse (Cape Grosso, 9°23′E) the Northern point of Corsica to the frontier between France and Italy (7°31′E). "On the Southeast." A line joining Cape Corse with Tinetto Island () and thence through Tino and Palmaria Islands to