Wind Cave is a unique natural formation located in the Black Hills of South Dakota. It is one of the longest caves in the world, known for its intricate boxwork formations, which are made of calcite. The cave was designated as a national park in 1903, making it the seventh national park in the United States. The cave's name comes from the strong winds that can be felt at its entrance, which are caused by changes in air pressure within the cave. Wind Cave is also home to diverse wildlife and is part of the larger Wind Cave National Park, which features scenic landscapes and hiking trails.