Willis Tower, formerly known as Sears Tower is a 108-story, 1,451-foot skyscraper in Chicago, Illinois. At the time of its completion in 1973, it was the tallest building in the world, surpassing the World Trade Center towers in New York, and it held this rank for nearly 25 years. The Willis Tower is the tallest building in the United States and the seventh-tallest freestanding structure in the world. The skyscraper is one of the most popular tourist destinations in Chicago, and over one million people visit its observation deck each year.
In March 2009, London-based insurance broker Willis Group Holdings agreed to lease a portion of the building, and obtained the building’s naming rights. On July 16, 2009, the building was officially renamed the Willis Tower. The building has appeared in numerous films and television shows set in Chicago.