I'm a severe claustrophobe. After getting trapped in a slide in my local McDonald's at five years old, I swore off all tight and dark spaces forever. So it's not entirely surprising that I couldn't ...

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 ...

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 ...