Willis Tower (formerly Sears Tower)

Standing 1454 feet high, this skyscraper is easily Chicago's most dominant structure and still holds the title of tallest building in the Western Hemisphere. Visitors can shoot to the top of the 110-story building via a 70-second elevator ride and catch magnificent views into Indiana, Michigan and Wisconsin from the 103rd floor Skydeck. If you are looking for thrill, step out onto "The Ledge," glass boxes extended from the side of the Skydeck with views 1,353 feet straight down. Informational exhibits for both adults and children teach the history of Chicago, the construction of the tower and interesting "did you know" facts.