High Quality Content by WIKIPEDIA articles! A national park is a reserve of natural or semi-natural land, declared or owned by a national government, set aside for human recreation and enjoyment, and protected from most development. While ideas for national parks had been suggested previously, what is held to be the first one established was the United States' Yellowstone National Park, established in 1872. An international organization, the International Union for Conservation of Nature (IUCN), and its World Commission on Protected Areas, has defined National Parks as its category II type of protected areas. The largest national park in the world meeting the IUCN definition is the Northeast Greenland National Park, which was established in 1974. According to the IUCN, there are now 6,555 national parks worldwide.