Willis Tower

The Willis Tower, originally known as the Sears Tower, is a 110-story, 1,451-foot skyscraper in Chicago's Loop. Designed by Bruce Graham and Fazlur Rahman Khan, it opened in 1973 and held the title of world's tallest building for nearly 25 years. Now the third-tallest building in the Western Hemisphere, its facade is anodized aluminum and black glass, and the base houses a retail complex called the Catalog. Over 1.7 million visitors annually head to the Skydeck, the highest observation deck in the United States, making it one of Chicago's top attractions. The tower is visible from far away and has appeared in many films and TV shows set in Chicago. The lower half once held Sears headquarters, but today major tenants include United Airlines and Willis Towers Watson.