Win Cave National Park is a United States national park 10 miles (16 km) 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 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. The cave passed Hoelloch cave in Switzerland on February 11th, 2006 to become fourth-longest in the world with 119.58 miles (192.45 km) of explored cave passageways. The cave's current length is 125.76 miles (202.39 km). Above ground, the park includes the largest remaining natural mixed-grass prairie in the United States.