This large marine protected area encompasses 87,500 km² (an area twice the size of Switzerland) and was created by an agreement between Italy, the Principality of Monaco, and France for the protection of marine mammals in the Mediterranean. Unlike most protected areas, it includes both coastal and deep-sea waters. A complex system of currents and the particular morphology of the seabed, which is steep and dotted with underwater mountains and deep canyons, make it one of the most productive areas in the Mediterranean. It is rich with small crustaceans, called 'Mediterranean krill'; this large quantity of zooplankton attracts various animals that feed on it, including cetaceans. The first to identify this area as particularly important for whales and dolphins and to propose the establishment of a transnational protected area was the Tethys Institute. With the help of many other organisations, the sanctuary was established in 1999.
Spotting whales or dolphins in their natural environment is an exciting and extraordinary experience that can be enjoyed in different ways: participating in organised whale watching day trips, in one’s own boat, or collaborating in scientific research on weekly citizen science cruises alongside the marine biologists of the Tethys Institute.
There is a code of conduct one must follow to avoid disturbing the animals when encountering them, which includes approaching them gradually from the side, moving in parallel to their route while maintaining a distance of at least 100 m, avoiding separating individuals from the rest of the group, and limiting the encounter to 20–30 minutes. In addition, if the animal repeatedly attempts to move away, it is recommended to leave the area immediately.