I had visited five national parks before I visited Mammoth Cave, including the Grand Canyon, but it was at Mammoth Cave that I truly fell in love with national parks. You see, in none of my five ...

If you come this far out on the Thumb, there is no way to get down ... hopefully a vast Grand Canyon wilderness, in the truest sense of the word, still exists. Your National Geographic Society ...

The Cave of the Winds Mountain Park in Colorado is home to the "Terror-dactyl" - a thrill ride that launches you 200 feet into a canyon. You reach speeds of 100 mph on the ride and you free fall ...