The
Gulf of Trieste (, , , ) is a very shallow bay of the
Adriatic Sea, in the extreme northern part of the
Adriatic Sea. It is part of the
Gulf of Venice and is shared by
Italy,
Slovenia and
Croatia. It is closed to the south by the peninsula of
Istria, the largest peninsula in the Adriatic Sea, shared between Croatia and Slovenia. The entire Slovenian sea is part of the Gulf of Trieste.