Sears Tower, now known as Willis Tower, is the tallest building in Chicago and superseding the Trump International Hotel and Tower and the Aon Center by 27 meter and 96 meter respectively. The elegant building is made with bronze-tinted glass and stainless aluminum. The building structure has a grand foundation and rises out rightly into massive spires at the top. While the locals can't get over the magnificence of the structure, the visitors in Chicago are dazed.

The Sears Tower Official Site

http://www.searstower.org/home.html

The building structure is carved out of nine framed tubes. The tubes are nine skyscrapers combined into one magnificent structure. The nine tubes continue to rise up to the forty-ninth story at which point two of the tubes stop ascending and the seven others continue to move upwards to the sixty sixth floor. Above that, two tubes create a rectangle and reach up to a height of 1450 feet.

Sears Tower in Chicago

http://www.aviewoncities.com/chicago/searstower.htm

The observation deck, called the skydeck, is situated at 412 m and it is the highest observation point in Chicago. The ledge at the observation deck extends 4.3 feet outwards, from where one can also look down. It may be a little frightening, but it is also one of the most spectacular sights one can ever see, thus making it a point of attractions for people from all over the world. The design of the building structure dwell on the fact of lateral strength, which helps the building withstand the strongest winds.

Wiki Info on Sears Towers, Chicago

http://www.en.wikipedia.org/wiki/Willis_Tower