Just 30 minutes from downtown Flagstaff, Sunset Crater Volcano National Monument offers a striking look at northern Arizona’s explosive past.

You'll feel like you're walking though Hawaii's national park when you tackle this short trail at Craters of the Moon in Idaho.

Geology is full of detective stories about the Earth's history, and a new paper in Geology by University of New Mexico ...

Visitors explore Wind Cave National Park in South Dakota. With 130 miles of explored passages, it is among the world’s longest cave systems and a popular spot for spelunking enthusiasts.

The Old Caves Crater Trail is one of the best hikes in Arizona for exploring caves built by the region's earliest inhabitants ...

In this video, we take you on a journey through Iceland’s most otherworldly natural wonders, from vast lava fields and volcanic craters to dazzling ice caves hidden beneath glaciers.

Here are new things to do in Flagstaff this summer, plus some old favorites. For more information, the Visit Flagstaff visitor center is in the historic downtown train station at 1 E. Route 66.

Tzion Maron became separated from his family at Lava River Caves northwest of Flagstaff on Wednesday, according to Coconino County Sheriff's Office.