At 136 miles, Jewel Cave is the second longest cave in the world. It is filled with calcite crystals and other wonders that make up the jewels of Jewel Cave National Monument. The current length of Jewel Cave is: 136.64 miles. More and more of the cave is discovered by explorers each year. 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.
