Geological Oddities

Glacial erratic or man-made dolmen? It probably wasn't druids.

This mountaintop lake bubbles and steams in a perpetual boil, thanks to its direct link to the Earth's interior.

A massive volcanic plug is now a protected area that hosts a number of bird species.

In a long-dry lake bed, these groups of massive stone pillars bear a striking resemblance to clumps of everyone's favorite fungi.

The second-deepest known cave on Earth, hidden in an extremely remote mountain region.

A lake formed in the basin of a massive impact crater takes the shape of an unbroken ring when viewed from above.

One of the most extreme deserts in the world, these snow-free valleys harbor life, despite the hostile environment.

Earth's greatest purely vertical drop at 4,101 feet.

An arresting arch punched straight through a mountain provides one of the most scenic spots, and challenging climbs, on the planet.

Unexplained bald patches in the landscape grow and recede over time, as though they are somehow alive.

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

Rising from the sea like a stone monster.

Mount Nyiragongo has erupted at least 34 times since 1882 and is home to the world's largest lava lake.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

Walls of stone rise up from sinkholes caused by underwater erosion.