A hotly contested micro-nation off the coast of Montserrat.

Think you have a tough job? Try carrying 200 kilos through a cloud of sulfur down the side of a volcano.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

A sulfuric hellscape in southern Italy.

A city continually buried under the ash of a volcano that has been erupting for more than 15 years.

Fire meets ice at the southernmost volcano on Earth.

This Canary island is a quintessential example of nature’s beauty, and its unbridled fury.

An isolated dive site teeming with cnidarians.

The unique ecosystem atop an Australian mountain is home to some colorful inhabitants.

This small primate research island is teeming with playing, fighting wild monkeys.

In paradise, feral pigs have claimed an island all to themselves.

This crescent-shaped sliver of sand is a magical haven for a herd of feral horses.

The world's largest bioluminescent area was undiscovered by science until 2005.

Granite outcropping that the state's tourism bureau doesn't promote because of its delicate ecosystem.

Curious cave that stays a cool 56 degrees all year long.

Explore the complex ecology of this multifaceted nature preserve by riverboat.

A lake in the middle of the tundra of Quebec is said to be the purest freshwater lake on Earth.

An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

Landbridge created by the South Korean version of Moses.

Splashes of blue in an otherwise monotonous lunar landscape.

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

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

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

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.