Kartchner Caverns State Park is like nature’s own subterranean art gallery, complete with stalactites, stalagmites, and enough “oohs” and “aahs” to fill a cavern. This hidden gem was kept secret for ...

Welcome to Arizona, where Mother Nature went all out with her crayons and sculpting tools ... The formations are so otherworldly that you half expect to see aliens peeking out from behind a column.

National Geographic revealed its annual Pictures of the Year issue. The photos show wildlife, scientific innovations, and ...