The Mort Lagoon, an extremely evocative naturalistic site, was originated by the overflowing of the Piave river in 1936, whose bed was modified in its last stretch after a big flood. The Mort stretches between Eraclea Mare and the mouth of the Piave river and it is a sea-lagoon, being supplied with water only by the flood-tides. Still uncontaminated, the Mort is characterized by shallow and calm waters with a sandy and muddy seabed, rich in phytoplankton. This is a very important site from a naturalistic point of view, enjoyable in every season, whose precious and delicate ecosystem is going through an extensive reclamation, aiming at the restoration of the original environment, that gives shelter to a great variety of plants and autochthonous animals.
The change of season corresponds to a change in the local fauna too: mussels, oysters, clams, crabs, grey mullets, flounders, soles, cormorans and terns, only to mention a few species.

The flora species are also numerous and peculiar: it is possible, for example, to see a great variety of water-plants living in salt-water.

To study and admire these peculiarities, the Territorial Laboratory for Environmental Education organises guided visits to the Mort Lagoon. At the Limosa Centre is also available an exhibition which is worth-visiting to get to know about the lagoon and the surrounding environment.