Check out 15 Fun Things to do in Flagstaff for more ideas ... El Malpais is a volcanic landscape home to lava flows, cinder ...

Rescuers hoisted a trapped caver 300 feet out of a lava tube in a Utah park, officials said. Santa Clara-Ivins Fire and Rescue on Instagram A trapped caver was hoisted 300 feet from a lava tube in ...

Beneath the surface of the Moon lie vast underground caverns, some of which are miles long and wider than football fields, and they may make for excellent settlement sites. Democrats aghast at ...