Lake Lesina is about 22 km long and 2.4 km wide on average. It is the ninth largest lake in Italy and the second largest in southern Italy. It is separated from the sea by a stretch of land covered by a 16 km long dune (the Isola Wood), to which it is connected via two canals, the Acquarotta and the Schiapparo.
The eastern part of the lake is home to the Lake Lesina Natural Reserve, a state nature reserve established in 1981 to protect the restocking of species.