Jewel Cave National Monument
With more than 129 miles surveyed, Jewel Cave is recognized as the third longest cave in the world. Airflow within its passages indicates a vast area yet to be explored. Cave tours provide opportunities for viewing this pristine cave system and its wide variety of speleothems including stalactites, stalagmites, draperies, frostwork, flowstone, boxwork and hydromagnesite balloons. The cave is an important hibernaculum for several species of bats.
Plane - The nearest major airport is 54 miles away in Rapid City, South Dakota.