Wind Cave National Park is a
United States national park north of the town of
Hot Springs in western
South Dakota. Established in 1903 by President
Theodore Roosevelt, it was the seventh U.S. National Park and the first
cave to be designated a national park anywhere in the world. The cave is notable for its displays of the
calcite formation known as
boxwork. Approximately 95 percent of the world's discovered boxwork formations are found in Wind Cave. Wind Cave is also known for its
frostwork. The cave is also considered a three-dimensional
maze cave, recognized as the densest (most passage volume per cubic mile) cave system in the world. The cave is currently the
sixth-longest in the world with of explored cave passageways, with an average of four new miles of cave being discovered each year. Above ground, the park includes the largest remaining natural mixed-grass
prairie in the United States.