2: Carlsbad Caverns, New Mexico
Be awed in beauty and wonder when you explore the deep rocky canyons, caverns, ancient sea ledges, thorny shrubs, and cactus of this cave tucked below the dessert terrain. There are about 119 caves you can explore which are formed with sulfuric acid and limestone. You can explore the Big Room and Main Corridor with self-guided cave tours or explore the underground with ranger-guided tours like the Bell Cord Room, Bit Frost Room, Bat Cave and the like. At night, you can see the exodus of the Brazilian free-tailed bats.
Address: 3225 National Parks Highway, Carlsbad Caverns National Park, NM