Add Yahoo as a preferred source to see more of our stories on Google. The Lava River Cave exhaled chilled air. I put on my sweatshirt, despite the hot July day. Though I'd been warned about the sudden ...

At a little more than a mile, Lava River Cave is Oregon’s longest intact lava tube. It’s also one of the most popular caves to explore in central Oregon. The cave is part of Bend’s Newberry National ...

No trip to Central Oregon would be complete without exploring one of the region's defining geological features: the vast expanses of hardened lava that diverted the Deschutes, formed mounds of gumdrop ...

Another world greets you just a short 30-minute drive from the Icelandic capital Reykjavik. Raufarhólshellir Lava Tunnel is a terrific example of a lava cave created following a volcanic eruption ...

While the vast majority of our nation’s natural wonders exist above ground, a select few parks, forests, and national monuments feature a hidden basement level. Mammoth Cave National Park, for example ...

If you're up for an adventure, the Lava River Cave delivers. Approximately 700,000 years ago when molten rock erupted from a vent in nearby Hart Prairie, the milelong Lava River Cave was formed. Today ...

In the not-too-distant future, the search for signs of life on Mars and the moon could see the next generation of robots exploring a new frontier: subsurface lava tubes. These missions could also help ...