For years, scientists have said that Venice will sink, given that it is a city built on a lagoon. Yearly, it succumbs to flooding, turning it's romantic piazzas and walkways into something far more dreary for its resident gondoliers.

But such talk may be premature as Venice carries out its first test of a multi-billion euro flood defence project.

Four giant gates have been lifted in front of the famous Lido island.

The project is roughly 80 percent complete.

The system is known as "MOSE," which is Italian for Moses.

Those involved in the project say the structure offers protection from tides up to three-meters, or almost ten feet high.

Critics say the project will be costly, difficult to maintain, and hurt the environment. But others say its a price worth paying to protect Venice from a fate under water.