Shaped and protected thanks to salt production, wetlands like the Salins d'Hyères on the Var coastline are sanctuaries that welcome remarkable fauna and flora and represent world-renowned environmental treasures. Wetlands are, moreover, the only natural environments subject to a special convention at the international level, the Ramsar convention, for their conservation and well-reasoned use. To date, 2,431 sites covering an area of almost 628 million acres (254 million ha) worldwide are recognized as being of international importance by this agreement, including 51 in France for an area of more than 9.1 million acres (3.7 million ha).