Lehman Caves were formed 550 million years ago. They have been protected as a national monument and extensively visited by tourists since 1922. The speleothems (cave formations) in this cave are spectacular. I have never seen a cave like it. The honeycombed maze of tunnels that makes up the longest cave system in Nevada is filled to the brim with stalactites, stalagmites, cave popcorn, shields and columns. It is absolutely remarkable. Definitely the most amazing thing inside Great Basin National Park.
