The Willis Tower observation deck, located on the 103rd floor of the tower, first opened on June 22, 1974. Today, 1.3 million visitors make their way to the deck, today known as Skydeck Chicago, every year. In January 2009, the owners of Willis Tower kicked off a major renovation of the Skydeck. Among the changes was the additon of retractable glass balconies. Known as The Ledge, the balconies can be extended approximately 4 feetfrom the facade of building and allow visitors to look through the glass floor to the street 1,353 feet below. The balconies officially opened on July 2, 2009.