The World Database on Protected Areas (WDPA) is compiled and managed by the World Conservation Monitoring Centre, an executive agency of the United Nations Environment Programme. It uses the IUCN and CBD definitions of protected areas to determine whether a site should be included in the WDPA. The extend to which each area and the resources within are protected can vary significantly. Currently, Marae Moana is the largest protected area in the world with a total area larger than Mexico (1,964,375 km2).