MOSE is a project intended to protect the city of Venice, Italy, and the Venetian Lagoon from flooding.
The project is an integrated system consisting of rows of mobile gates, installed on the seafloor at the Lido, Malamocco, and Chioggia inlets, that can be raised to temporarily seal off the Venetian Lagoon from the Adriatic Sea during acqua alta high tides. From Wikipedia
