Willis Tower Willis Tower The Willis Tower, built as and still commonly referred to as the Sears Tower, is a 110-story, 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 rebuilt World Trade Center site in 2014. The building is considered a seminal achievement for its designer Fazlur Rahman Khan. The Willis Tower is the second-tallest building in the
Center City Tower (Philadelphia) Center City Tower (Philadelphia) Center City Tower was the working name of a formerly proposed skyscraper in downtown Philadelphia. Designed and proposed by the firm now known as KlingStubbins (designers of Philadelphia's Penn Center and Bell Atlantic Tower), the building would have risen to a height of 1,050 feet (320 m) and 75 stories, making it the tallest building in The United States outside New York and Chicago, surpassing the height of the Bank of America Plaza in Atlanta. With a floor area of , it is one of the largest in Center City. The building was designed with an