There are many definitions of a national park available in an international context including the following concise definition: "National Parks exist to conserve natural plant and animal communities and scenic landscapes which are both extensive and of national importance and, under conditions compatible with that purpose, to enable the public to visit and appreciate them." All of Ireland's national parks comprise lands which have been acquired by the State for the purpose of nature conservation and are established to recognise such State-owned lands as national parks. Successive Governments have accepted the definition of a national park set out by IUCN, the World Conservation Union. The IVth IUCN World Congress on National Parks and Protected Areas defined a protected area as, "An area of land and/or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means."