(YouTube link)
Have you been wondering what the most extreme thing to do in Toronto is? Me too! Let's wonder no longer: it's the Edge Walk at the CN Tower! For $175, some really enterprising Canadians will place you in a harness and send you out along the edge of one of the world's tallest buildings and let you walk a circle 116 stories above the ground while strapped to an overhead railing. Not in this lifetime, if you're wondering, but feel free to try it yourself!
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Here in Las Vegas, the Stratosphere lets you jump off. You're attached to a cable for a controlled fall, but still!