A bird flies beneath my feet, gliding under the clear glass floor of a horseshoe-shaped structure that juts 70 feet from the rim of the Grand Canyon. The canyon floor is more than 4,000 feet below.
Maybe you've gone to the top of the Empire State Building and looked down at cars that seem like Matchbox toys. From the Grand Canyon Skywalk, you are more than three times farther from the ground below than when you stand at the top of the Empire State Building.