This glass box on top of the Willis tower lets you stand 1,353 feet above Chicago

The Ledge is a glass box on the 103rd floor of the Willis Tower, the eighth-tallest building in the world and the tallest building in the Western hemisphere. At an altitude of 1,353 feet you can see up to 50 miles and four states. The Ledge attracts more than 1.7 million visitors annually.