Underwater Stalagmites

Lechuguilla Cave, part of Carlsbad Caverns National Park in New Mexico. Photo Copyright © Michael Nichols

Crystal clear water surrounds stalagmites in Lechuguilla Cave, part of Carlsbad Caverns National Park in New Mexico. This once nondescript cave was launched into international stardom in 1986 when cavers broke through a closed passage and discovered numerous walkable tunnels. Since then, more than 100 miles (160 kilometers) of tunnel have been mapped, making it the third longest cave in the United States and the fifth longest in the world.