Which gulf forms the northernmost part of the Adriatic Sea and includes Venice Lagoon?

The gulf forming the northernmost part of the Adriatic Sea and associated with the Venice Lagoon is the Gulf of Venice. It occupies the northern Adriatic between northeastern Italy, southwestern Slovenia and western Croatia.

The Gulf of Venice is an informal geographic designation rather than a gulf formally recognized by the International Hydrographic Organization. Under its usual definition, it extends from the Po Delta and the Italian coast toward the Istrian Peninsula. The Gulf of Trieste is often treated as a smaller, distinct gulf within its northeastern area.

Several major rivers flow into the Gulf of Venice, including the Tagliamento, Piave, Adige, Isonzo, Dragonja and Brenta. Venice and Chioggia lie along its Italian shore, while Trieste and Koper are important cities in the wider northern Adriatic region.

The Venice Lagoon is an enclosed, shallow marine lagoon connected to the Adriatic by three inlets: Lido, Malamocco and Chioggia. It is not the same feature as the Gulf of Venice, but it lies within the gulf's coastal environment. The Gulf of Trieste is the principal competing answer, but it is a smaller subdivision rather than the broad regional gulf described here.