Hidden inside Vietnam’s Phong Nha-Ke Bang National Park is Son Doong, the largest cave on Earth. It’s so vast that a Boeing ...

CEDAR FALLS — A team of NASA-funded University of Northern Iowa researchers is exploring some of the deepest caves in the United States to uncover secrets about life in extreme environments — and ...

BOB MARSHALL WILDERNESS, Mont. — Montana calls itself home to the first and now second deepest cave in the continental United States. A team discovered Bobsled Cave in the Bob Marshall Wilderness, and ...

The Hranicka Abyss is at least 1,325 feet deep, and likely goes down further. — -- A team of explorers believe they have discovered the deepest known underwater cavern the world in eastern Czech ...

Hells Canyon, the deepest river gorge in the United States, likely got rapidly carved 2.1 million years ago when a shifting landscape in Idaho caused a giant lake to start overflowing. That's ...

This summer, Richard Brown and five others from around the country hiked almost 30 miles into the Bob Marshall Wilderness to explore an underground wilderness few have seen. More people have walked on ...