The Ledge, Willis Tower
The Willis Tower (perhaps better known by its previous name, the Sears Tower) has long stood as one of the tallest buildings in the United States. Attached to it are four small glass balconies that jut out from the side of 103rd floor of the building. Sightseers and thrill-seekers can look down through the glass floors of these balconies to the street, which is 1,353 feet below.
The views are incredible. Not only can you get a different angle of one the world's most famous skylines, but you can also see almost 50 miles into the distance. On a clear day, that's far enough to see four different states on a: Illinois (obviously), Michigan, Indiana and Wisconsin.