This working paper provides a global overview of the current coverage of existing World Heritage sites with wetland and marine values and suggests potential wetland areas which may merit future nomination to the World Heritage List. Wetlands are among the most productive natural environments on earth. They provide substantial social and economic benefits to humans as well as habitat for numerous species. With only an estimated 5.7 million sq. km of wetlands remaining in the world, they continue to be one of the most threatened biomes.