The National Park Service The National Park Service manages public lands, set aside by Congress, which embody the cultural and natural heritage of the American people. These public lands serve as classrooms where visitors may view historic artifacts and structures, and interact with the natural world. Every ranger presentation, whether for tour groups, families, or young people, has an educational component. Visitors of all ages learn who signed the Declaration of Independence at Independence Hall; what caused the formation of Mammoth Cave; or why mangroves and alligators are important in the Everglades ecosystem.