Gaze up at the night sky, ride horseback through a canyon and see hoodoos up close at Bryce Canyon. Fly with thousands of bats, explore incredible formations,and trek by headlamp through a cave at Carlsbad Caverns. Fly over an active volcano, explore a lava tube, and look out across volcanic cliffs at Hawai'i Volcanoes. Rappel into a crevasse, kayak through icebergs and watch a glacier recede at Kenai Fjords.Dive a shipwreck, swim through the third-largest coral reef in the world, and tour a Civil-War era fort at Dry Tortugas. Discover 5 national parks from the comfort of your own home.