A national park is a government-protected area designated for conservation due to its outstanding natural, historic, or cultural significance, and is typically open to the public for enjoyment and education. The first widely recognized national park is Yellowstone National Park in the United States, established in 1872, though older protected areas like the Tobago Main Ridge Forest Reserve (1776) and Bogd Khan Uul Mountain (1778) predate it, and Parks Canada (1911) holds the title of the world's oldest national park service. The International Union for Conservation of Nature (IUCN) defines a national park as a Category II protected area, and in 2006, 6,555 parks worldwide met its strict criteria. The largest national park meeting this definition is Northeast Greenland National Park, established in 1974, covering an immense 972,000 square kilometers. However, many areas called "national parks"—such as the Swiss National Park or the Everglades—actually fall under other IUCN categories, as the official definition has evolved to include specific benchmarks like minimum size, legal protection, and prohibitions on resource exploitation.