Volcanoes

These neon green and blue lakes are in the shadow of two huge volcanoes.

Standing 26 feet high and 13 feet in diameter, is this the world’s smallest volcano?

Hawai'i Volcanoes National Park is home to one of Polynesia’s largest petroglyph fields.

This lava tube cave was once a Cold War fallout shelter.

Hawaii’s largest cemetery rests inside an extinct volcano crater.

The steep slope known as “Ob Hill” overlooks an Antarctic research station.

Halfway up a volcano at the edge of the world’s largest salt flats is a cave with seven mummies.

These four small islands contain unique hexagonal rock formations.

The easternmost point of Hawai'i plays a prominent role in local legends and is home to a lighthouse that survived a lava flow.

This color-changing crater lake in El Salvador is occasionally impenetrable to sunlight.

An unusual double cinder cone with a bent oval crater, in the Lunar Crater Volcanic Field.

This volcanic crater lake is renowned for its perfectly round shape, stunning blue-green waters, and unique geological properties.

Some 46,000 years ago, a volcanic eruption led to a flooding event that carved this short canyon with steep vertical walls.

An outdoor gallery of sculptures chiseled from a unique stone that deemed Arequipa's old town a UNESCO World Heritage Site.

An incredibly salty lake inside the crater of an extinct volcano.

Two geologically young and nearly circular volcanic subsidence craters, each about a half-mile in diameter, abruptly break the nearly featureless Snake River Plain.