A jungle inside a cave? A roof collapse long ago in Hang Son Doong ... Stands of bamboo and other vegetation cover mounds of limestone here, making the place all but impenetrable.

Lechuguilla Cave at Carlsbad Caverns is the deepest limestone cave in the country, and the fifth-longest known cave in the world. Read more about Oil and Gas Development Delayed Near Carlsbad Caverns ...

A member of the Iranian Caving and Speleology Association confirmed the discovery of this limestone cave in Barzok by a local resident. The cave features multiple chambers and passageways and ...

Clip: Under most of Florida is a limestone bed ... a cavern forms. When the cavern gets too big, the ground above it collapses, dragging a typically circular section of the Earth's crust down ...

The park contains over 85 known caves. This includes Lechuguilla Cave, the nation's deepest limestone cave at 1,567 feet (478m) and third longest . Life in the park includes approximately 750 ...