Plot Summary:Beneath our sunlit world lies an unknown universe of breathtaking caverns, treacherous passageways, and absolute darkness. This video explores a new cave, New Mexico's Lechuguilla, first penetrated in 1986; it contains gypsum chandeliers, gnarled calcite columns, and jewel-like lakes. The video also includes footage from the 1972 expedition that discovered a passageway linking the Mammoth and Flint Ridge Cave systems, creating the longest cave network in the world.