What’s to Know about Willis Tower?

The Willis Tower, formerly known as Sears Tower, is a 110 storey skyscraper in Chicago, United States of America, was once the tallest building in the world, occupying the top spot for a period of around 25 years, from 1973 to 1998, until the Petronas Twin Towers in Kuala Lumpur, Malaysia, broke the record. While Burj Khalifa, Dubai, holds the current world record, Willis Tower is now the eighth tallest