Most people think of visiting big cities, national parks, and beaches when they plan a U.S. trip. There’s hardly anyone who’s ...

That fluorescence changes color depending on which impurities are trapped in the ... Scientists from the University of Northern Iowa explore caves and map the colors emitted by the rocks in different ...

Discovered in 1928, the waterfall is located deep within Lookout Mountain, accessible via guided tours through the caverns. The highlight of the tour is the breathtaking sight of the 145-foot ...

The caverns started out as limestone before the ... As for why glacial silt produces such a shocking blue-green color? An accident of physics. The pulverized dust that used to be mountains happens ...