World’s Tallest Building – Burj Khalifa
The Burj Khalifa (Arabic for “Khalifa Tower”; known as the Burj Dubai prior to its inauguration in 2010, is a skyscraper in Dubai, United Arab Emirates. With a total height of 829.8 m (2,722 ft) and a roof height (excluding antenna) of 828 m (2,717 ft), the Burj Khalifa has been the tallest structure and building in the world since its topping out in late 2008. The construction of this tallest skyscraper started on 21st September, 2004 and got complete on 1st October, 2009. (Source : Wikipedia)
Here is a video on the construction of world’s tallest skyscraper and one of the multi-functional building in Dubai.