Willis Tower

Buildings Construction 








The Willis Tower, built as and still commonly referred to as the Sears Tower, is a 110-story, 1,450-foot (442.1 m) skyscraper in Chicago, Illinois. At completion in 1973, it surpassed the World Trade Center towers in New York to become the tallest building in the world, a title it held for nearly 25 years; it remained the tallest building in the Western Hemisphere until the completion of a new building at the World Trade Center site in 2014.

Willis TowerThe building is considered a seminal achievement for its designer Fazlur Rahman Khan. The Willis Tower is the second-tallest building in the United States and the Western hemisphere – and the 16th-tallest in the world. More than one million people visit its observation deck each year, making it one of Chicago's most-popular tourist destinations. The structure was renamed in 2009 by the Willis Group as part of its lease on a portion of the tower's space.

As of December 2013, the building's largest tenant is United Airlines, which moved its corporate headquarters from the United Building at 77 West Wacker Drive in 2012 and today occupies around 20 floors with its headquarters and operations center.

The Willis Tower observation deck, called the Skydeck, opened on June 22, 1974. Located on the 103rd floor at an elevation of 1,353 feet (412.4 m), it is the highest observation deck in the United States and one of Chicago's most famous tourist attractions. Tourists can experience how the building sways in wind and see far over the plains of Illinois and across Lake Michigan to Indiana, Michigan, and Wisconsin in clear conditions. Elevators reach the top in about 60 seconds, allowing occupants to feel the change in pressure as they ascend. The Skydeck competes with the John Hancock Center's observation floor a mile and a half away but reaching 323 feet (98.5 m) lower. Some 1.7 million tourists visit annually. A second observation deck on the 99th floor serves as a backup. The tourist entrance can be found on the south side of the building along Jackson Boulevard.


The Willis Tower remains the second tallest building in the Americas (after One World Trade Center) and the Western Hemisphere. With a pinnacle height of 1,729 feet (527 m), it is the third-tallest freestanding structure in the Americas, 86 feet (26.2 m) shorter than Toronto's CN Tower. It is the eighth-tallest freestanding structure in the world by pinnacle height. More details