Willis Tower, formerly known as the Sears Tower, is one of the most iconic skyscrapers in Chicago, Illinois. Completed in 1973, this architectural landmark stands 110 stories tall and was once the tallest building in the world. Designed by Skidmore, Owings & Merrill, the tower features a distinctive bundled-tube structure that gives it both strength and a bold, modern look. Willis Tower is home to offices, retail spaces, and the famous Skydeck, where visitors can step onto glass ledges and enjoy breathtaking views of the city and Lake Michigan.