Willis Tower, Chicago

Willis Tower, formerly known as the Sears Tower, is an iconic skyscraper that defines the skyline of Chicago, United States. This towering structure, standing at an impressive height of 1,450 feet (442 meters), was completed in 1973 and held the title of the tallest building in the world for nearly 25 years until 1998. It remains one of the tallest buildings in the United States and an emblem of Chicago's architectural ambition.

The Willis Tower is not only a marvel of engineering but also a major tourist attraction, offering breathtaking views of the city and its surroundings. Visitors can ascend to the Skydeck on the 103rd floor, which is the building's highest observation deck, located at 1,353 feet (412 meters) above street level. The Skydeck features glass-floored ledges that extend four feet from the building, providing a thrilling experience of standing in the air above the city.

The skyscraper was originally commissioned by Sears, Roebuck & Co. to house its corporate headquarters and was designed by architect Bruce Graham and structural engineer Fazlur Rahman Khan of the architectural firm Skidmore, Owings & Merrill. Its innovative bundled-tube design was a pioneering approach to skyscraper construction, enabling the tower to reach unprecedented heights.

Willis Tower is not just a sight to behold but also a hub of activity, housing office spaces, restaurants, and broadcast facilities. It is a key feature in the Chicago Loop, the city's bustling business district. The Skydeck attracts over 1.7 million visitors annually, who come to enjoy the panoramic vistas of up to four states, making it one of the most visited destinations in Chicago.

The building is open to the public every day of the year, and tickets to the Skydeck can be purchased for daytime or evening visits. At night, Willis Tower stands out with its distinctive antenna lighting, which often displays colors for holidays and special events.