Burj Khalifa , formerly known as Burj Dubai, is a skyscraper in Dubai, United Arab Emirates, and the tallest man-made structure ever built, at 828 m (2,717 ft). Construction began on 21 September 2004, with the exterior of the structure completed on 1 October 2009. The building officially opened on 4 January 2010. The building is part of the 2 km2 (490-acre) flagship development called Downtown Burj Khalifa at the “First Interchange” along Sheikh Zayed Road, near Dubai’s main business district.