The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of wetlands. Adopted in 1971, it entered into force in 1975 and as of May 2022 had 172 contracting parties. Greece acceded on 21 December 1975 and has ten Ramsar sites as of May 2022, with a total surface area of .