Carlsbad Caverns is a maze of underground caves born from an ancient tropical reef. The caverns house North America's largest cave chamber, "the Big Room," which boasts a floor area of 8.2 acres — ...
Archaeologists and students digging in Blätterhöhle cave uncovered a 9,000-year-old fireplace (above), flint arrowheads and a bone harpoon. Photo from LWL-AfW Olpe / Michael Baales Inside a cave ...