Volcanoes

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.

See the imprints of ancient trees, burned and preserved by lava.

A town half-submerged in volcanic mud has become a pilgrimage site for devotees of one of the tragedy's victims.

This lake with an inactive volcano underneath is often said to be bottomless.

Safely view the Soufrière Hills volcano, which has been erupting since 1995.

A peninsula on a peninsula that becomes an island at high tide.