SAN VICENTE PACAYA, Guatemala -- It's the only place in the world where you can hike up a volcano and once done, enjoy an artisanal pizza cooked inside a volcano! Based in Guatemala, Pizza Pacaya was ...

The Chauvet-Pont D'Arc cave is one of the most famous underground caverns in the world, housing one of the oldest and best-preserved collections of prehistoric cave paintings ever discovered. Now, ...

(CNN) — A mile and a half beneath the ocean’s surface, the seafloor seems nearly as alien as the surfaces of other planets. Deep-sea volcanic ridges, formed by the collisions of tectonic plates, ...

A team of Chinese researchers has identified eight caves in Mars’ Hebrus Valles that may have been sculpted by water. These ...

Mountaineers, cavers, and scientists ventured into the inhospitable caves at the giant volcano’s peak to learn more about how this frozen environment is changing over time. Tabby Cavendish, a ranger ...

A mysterious pit on the flank of an ancient volcano on Mars has generated excitement recently because of what it could reveal beneath the surface of the Red Planet. Here's what that means. First ...

Fresh orbital images and new geological analysis have revealed eight mysterious caves on Mars that appear unusually well suited to protect traces of life. Together, these caverns, portals and ...

Scientists have identified eight mysterious water-shaped caves on Mars, unlike volcanic tunnels, raising fresh hopes these ...

One the John Muir's finest pieces--and one of my favorite pieces of writing--is about surviving a sudden snowstorm with the help of fumaroles. The whole thing is very much worth reading. Our ...