He thought he was checking a sinkhole. What he actually found was the beginning of a cave no one may have entered before.

This extraordinary animal supports a secret subterranean ecosystem.

A prehistoric human skeleton has been found in a flooded Mexican cave, with researchers believing it was likely placed there as part of a ritual. Cave-diving archaeologist Octavio del Río discovered ...

Deep in Michigan’s U.P., this little-known preserve leads to a striking underground world that feels far wilder than most ...

The British Vietnam Caving Expedition Team has discovered a sinkhole-like cave featuring an underground waterfall in Phong ...

Sinkholes are common in Florida. There's even "Sinkhole Alley" that's not too far from Orlando. If you're new to the concept, ...