Mexico is one of the best countries in the world for scuba diving. Its coastline boasts the Mesoamerican Barrier Reef, the largest barrier reef in the Western Hemisphere (and the second largest in the ...

Some of the Earth's most incredible features lie beneath its surface. Caves often hold fascinating secrets, from the world's largest underwater cave, which is full of human remains, to the Cave of the ...

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 ...