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 ...

Beneath the Earth’s surface lies a world so extreme and isolated that it seems more like an alien planet than part of our own. Veryovkina Cave, the deepest known cave on Earth, plunges a staggering ...

Brett Hemphill, a noted diver, died while exploring Phantom Springs Cave in Texas, officials say. Screengrab from Facebook post by Karst Underwater Research. A renowned diver recently died while ...

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 ...

The idea of disappearing into some of the world’s deepest pockets submerged in pitch black water, with only the sound of heavy breaths for company, would bring on a shiver for many.

Centuries of eruptions on the Big Island have created hidden networks of passages beneath volcanoes. In December 2016 a large lava delta formed by Kilauea volcano sank into the sea, exposing the mouth ...

Archaeologists excavating a paleolithic cave site in Galilee, Israel, have found evidence that a deep-cave compound at the site may have been used for ritualistic gatherings, according to a new paper ...