Sears Tower is a 108-story, 1,450 feet (442 m) skyscraper in Chicago, Illinois. Currently, Sears Tower is the tallest skyscraper in the United States. The Sears Tower Skydeck observation deck opened on June 22, 1974 and is located on the 103rd floor of the tower. It is 1,353 feet (412 m) above ground and is one of the most famous tourist attractions in Chicago. Tourists can experience how the building sways on a windy day. It takes about 60 seconds to soar to the top in either of two special, Schindler Group elevators. 1.3 million tourists visit the Skydeck annually. In January 2009, the Skydeck began a major renovation including the installation of “glass balconies” extending approximately four feet over Wacker Drive from the 103rd floor. The all-glass boxes allow visitors to look through the floor to the street 1,353 feet (412 m) below. The boxes, which can bear five tons of weight (about 4.5 metric tonnes), opened to the public on July 2, 2009.