Grand Canyon West Rim - Skywalk, Arizona . The Skywalk is suspended 4,000 feet above the Colorado River. This $60 million dollars bridge can withstand the weight of 71 fully loaded Boeing 74 airplanes (more than 71 million pounds). It is the tallest man-made structure in the world. From the bridge, you can step out onto the glass floor for a 720 degree view of the Canyon