Burj Khalifa , known as Burj Dubai before its inauguration, is a megatall skyscraper in Dubai, United Arab Emirates. It is the tallest artificial structure in the world, standing at 829.8 m (2,722 ft). Construction of Burj Khalifa began in 2004, with the exterior completed in 2009. The primary structure is reinforced concrete. The building opened in 2010, as part of the new development called Downtown Dubai. It is designed to be the centerpiece of large-scale, mixed-use development. The decisio