Got acrophobia? You will now
For Christ's sake, don't look down!
This is a rendering of the Grand Canyon Skywalk, a transparent bridge that when complete next year will hang 4,000 feet above the Colorado River, offering no doubt spectacular views of the canyon below. For comparison's sake, the tallest building in the world is a paltry 1,671 feet tall, while the tallest skyscrapers in most American cities are only around 500.
Supposedly the bridge is strong enough to hold the weight of 71 fully loaded 747s stacked on top of one another and simultaneously sustain winds of more than 100 miles per hour from eight different directions... but even so, if a busload of sumo wrestlers was out there I think I might hang out in the gift shop for a while before checking it out for myself.