Which is the tallest building in the world? You will answer without hesitation that it is the Burj Khalifa in Dubai, U.A.E. What if I were to ask you which building held that spot before the Burj Khalifa? The fact-seekers and quiz-heads might be able to answer that one (Psst… It is Taipei 101 in Taipei, Taiwan). But what if I were to ask you the one before that? And before that? Even trivia-hunters might not be able to give that easily. While it might not be easy to recollect each of these buildings, progression in records give a sense of how far things have come. In the case of tallest buildings, it can in fact go back thousands of years to the Great Pyramid in Egypt. Sears Tower is the answer to that fourth and final question (Petronas Towers in Kuala Lumpur, Malaysia, is the answer to the other question) and the building that we will be looking closer at. 25 years of fameOn May 3, 1973, construction workers involved in building Sears Tower bolted the last girder in place, making Sears Tower (now called Willis Tower) the tallest building in the world. A 110-storey skyscraper in downtown Chicago, U.S., the Sears Tower held that place of prominence for nearly a quarter of a century, until Malaysia’s Petronas Towers eventually went past it in 1998-1999. The first building ever to go past the 1,450 feet mark (that is more than 440m and over a quarter of a mile), the Sears Tower stands out for its unique design (more on that in a bit) and sleek black steel exterior. When it was built, it was the highest permissible height allowed by the Federal Aviation Administration. Sears, Roebuck and Company was the biggest retail company on the planet in the 1960s. With over 3,50,000 employees, and most of them in the Chicago area, Sears decided to build a central headquarters that also signalled the company’s ambitions and success. The result was the Sears Tower in 1973. The merchandising department alone occupied nearly 50 floors of the building in its heyday. By 1988, however, merely 15 years after the completion of the building, Sears sold the tower and moved out its 8,000 employees (yes, you read that right!) as part of a restructuring effort. The skyscraper’s name was changed to Willis Tower in 2009 when a London-based insurance company called Willis Group Holdings struck a deal to lease office space in the tower. The name might have been officially changed, but most people, especially those who’ve lived and worked in its vicinity, continue to call it Sears Tower.