One of the world's longest and most complex caves and 28,295 acres of mixed-grass prairie, ponderosa pine forest, and associated wildlife are the main features of the park.
The cave is well known for its outstanding display of boxwork, an unusual cave formation composed of thin calcite fins resembling honeycombs.
The park's mixed-grass prairie is one of the few remaining and is home to native wildlife such as bison, elk, pronghorn, mule deer, coyotes, and prairie dogs.
* Hot Spring 
Located in southwestern South Dakota, Badlands National Park consists of 244,000 acres of sharply eroded buttes, pinnacles and spires blended with the largest, protected mixed grass prairie in the United States. The Badlands Wilderness Area covers 64,000 acres and is the site of the reintroduction of the black-footed ferret, the most endangered land mammal in North America.