Adriatic Sea (ancient Adria or Mare Adriaticum), arm of the Mediterranean Sea, southern Europe, between the eastern coast of Italy and the western coast of the Balkan Peninsula. At the southern extremity is the Strait of Otranto, which connects it with the Ionian Sea. The Gulf of Venice, in the north, and the Gulf of Trieste, in the north-east, are the principal Adriatic embayments. The western coast is comparatively low and has few inlets, and the north is marshy and edged with lagoons. On the east the Albanian coast is steep and rocky, and the coasts of Bosnia and Herzegovina and Croatia are fringed with islands. More than 1,000 islands line the coast of Croatia, many covered with high mountains that drop right into the sea. The area of the sea is about 155,000 sq km (60,000 sq mi). The rocky eastern coasts are dangerous for mariners in the winter because of the prevailing north-eastern gales (bora). Trieste, Venice, Ancona, Bari, and Brindisi, all in Italy, are the chief ports. The fisheries of the Adriatic are highly productive, especially on the east coast, where lobsters and sardines are plentiful. The striking landscape, blue waters, and mild climate make the Adriatic a popular tourist destination.