I'm not in particularly afraid of heights, but this video kind of had me freaking out.  Check out these tourists swimming in 'The Devil's Pool' which is way to close to the edge of a waterfall.

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I guess this a pretty regular tourist thing to do when you head over to Zambia, but there is no way in hell I would do this.  There's a guide there that's supposed to help you, but what is he going to do if you go over the edge?  Nothing, other than watch you die.

Source: Fark