The Venetian Lagoon is the enclosed bay of the Adriatic Sea in which the city of Venice is situated. Its name in the Venetian language, Laguna Veneta— cognate of Latin lacus, "lake"— has provided the international name for an enclosed, shallow embayment of saltwater, a lagoon.
The Venetian Lagoon stretches from the River Sile in the north to the Brenta in the south, with a surface area of around 550 square kilometres (210 sq mi). It is around 8% land, including Venice itself and many smaller islands. About 11% is permanently covered by open water, or canal, as the network of dredged channels are called, while around 80% consists of mud flats, tidal shallows and salt marshes. The lagoon is the largest wetland in the Mediterranean Basin.
It is connected to the Adriatic Sea by three inlets: the Lido, Malamocco and Chioggia inlets. Sited at the end of a largely enclosed sea, the lagoon is subject to high variations in water level, the most extreme being the tides known as the acqua alta (Italian for "high waters"), which regularly flood much of Venice.