Formerly named the Sears Tower, the Willis Tower soars 1,451 feet over the Chicago Loop’s west side. It was the tallest building in the world for 25 years after its completion in 1973. The Skydeck on the 103rd floor provides over one million visitors a year with breathtaking vistas of downtown. If you are adventurous, you will also love walking into the all-glass box. This suspended lookout provides a vertigo-inducing view of the street 1,353 feet below. Approximately 30,000 people live in The Loop.