PBS
Nova: Jewel of the Underground
Take a virtual tour of Lechuguilla, a cave discovered in 1986, which turns out to be one of the biggest in the Americas. Twelve different pictures of interesting formations reveal the reason the park service has decided to keep it off...
Other
Glossary of Speleological and Caving Terms
This site features a glossary of speleological and caving terms. This resource is easy to use and gives a an adequate definition for each.