Explorers searching for a cave rumored to run for miles descended into a massive underground system filled with cold air and ...

Deep within the flooded chambers of a remote Mexican cave, explorers initially mistook a glinting object for a piece of 21st-century trash. But what they had actually uncovered was something far more ...

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 ...