Hidden beneath the surface lies a cave carved by an endless underground river. In this video, we venture deep into this water ...

Hidden beneath the surface, we discovered a powerful underground river flowing through a vast cave system. The roar of the ...

These three destinations are top-notch for underwater natural wonders, according to our readers. Find out where to go for the ...

In a hard-to-reach cave of northeastern India, a “slender” river creature with “fleshy” lips tucked itself under a rock. A ...

The Shoshone Ice Cave is actually a prehistoric lava tunnel carved not by water, but by fire and is ... "This is all natural lava flow here that we're walking on," Wallace said.