Afraid of heights? These may not be the videos for you. Alain Robert, the real-life spiderman, scales towering monuments across the globe—sans ropes, or security of any kind, for that matter. Don't slip, dude!

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This guy is a YouTube legend. He's climbing the New York Times building in NYC in the video up top. If you'd like more sky-high action, check out 15 skyscrapers that will never see the light of day, unbelievable Arabian monoliths, the many towers of Babel, or some remarkable accidental masterpieces—cooling towers. [Oobject]