A national park refers to an plot of land set aside by a national government and usually designated as an area free of development. Often, national parks include pristine wilderness areas or other pieces of environmental heritage which the nation has deemed worthy of preservation. In the United States, national parks also include historic areas and monuments to scientific achievement. Within the United States, the National Parks Service is managed by the Department of the Interior, which manages approximately one-fifth of the surface land in the United States.

The National Park Service was founded in 1916 by Woodrow Wilson, who signed the National Park Service Organic Act. The act established the service and set forth the regulations which would govern the National Parks. The National Parks of the United States are a heritage which all citizens can enjoy, and are aimed at preserving wilderness areas, history, and wild life for future generations. Many Americans have visited at least one National Park during their life times, and in a system with 390 designated areas, there will always be more National Parks to visit.

The National Park Service employs tens of thousands of people; even more during the summer. The Service is represented by an arrowhead, standing for archaeological and historical values, which surrounds a sequoia tree and bison, representing vegetation and wildlife. The crest also includes mountains and a river to symbolize the scenic and recreational uses of the National Parks. The role of the National Park Service has evolved since 1916, with several reorganizations aimed at greater efficiency and service. There has also been debate over use of the National Parks, especially surrounding off road vehicles and other such disturbances.

The first National Park was Yellowstone National Park, established in 1872. Yellowstone National Park was set aside to preserve the land for the enjoyment of all, and restricted sale, development, or settlement. The Department of the Interior managed Yellowstone National Park as a unique entity until 1916, when the National Park Service Organic Act was passed. The National Parks have been a popular destination for Americans ever since, with over 280 million people visiting the National Parks in 1999. Alaska houses the largest National Park, Wrangel-St. Elias, with 13.2 million acres of land. The smallest is Thaddeus Kosciuszko National Memorial in Pennsylvania, which has an area of 0.2 acres.

Guests in a National Park can stay in luxurious accommodations like the Ahwahee hotel at Yosemite or simple camping sites. For many National Parks, reservations are recommended, especially in the Summer which is peak traveling season. All National Parks also have an entry fee, which varies widely in price. Many travelers purchase a National Parks Pass, which allows admission to all National Parks for one calendar year.