In December 2016 a large lava delta formed by Kilauea volcano sank into the sea, exposing the mouth of a lava tube. A lava ...

Deep beneath a limestone ridge in the Western Caucasus lies a shaft so profound that reaching its floor requires days of rope work, camps clipped to sheer walls, and a constant fight against flooding.

The deepest caves on Earth are still being studied by scientists. They are unique environments created over millions of years of geological processes. They usually occur in areas rich in limestone ...

Mysterious trenches stretching for kilometers across southern Australia's Nullarbor Plain have been revealed as the surface footprints of deep, hidden ancient cave systems. New research involving ...

Stretching more than 200,000 square kilometers (77,000 square miles) across southern Australia, the vast, flat plains of the Nullarbor mark one of the world's largest regions of limestone. It formed ...

Beneath the island’s rainforest, explorers search for new discoveries deep within some of the Earth’s largest, longest, and ...