This park is home to one of the world's longest and most complex caves, amid 28,000 acres of mixed-grass prairie, ponderosa pine forest, and a grand assemblage of native wildlife.

Wind Cave is renowned for its outstanding display of "boxwork," an unusual cave formation composed of thin calcite fins resembling honeycombs.

The park's mixed-grass prairie ecosystem is one of the few remaining, and is home to native bison, elk, pronghorn, mule deer, coyote, and prairie dog towns.

• Wind Cave National Park -

• Take a ranger-led tour of the cave for which the park is named. Three cave tours are available year-round; two of them are 0.5 mile, the other is 0.25 mile. They follow paved, lighted walkways through underground passages decorated with boxwork and other fascinating cave formations.