Burj Dubai now BURJ KHALIFA - OPENING CEREMONY! Dubai , UAE; January 4, 2010: The world's tallest tower, developed by Emaar Properties, was unveiled tonight to a crowd of thousands and the world in a crescendo of fireworks, lasers and fountain displays. The official height of the tower, unveiled as 'Burj Khalifa', was announced as 828 metres (2,716.5 ft). A closely guarded secret, the official height of Burj Khalifa was flashed onto a giant screen before an estimated crowd of more than 400,000, as lasers and fireworks lit up the night sky. Fireworks cascaded from the tower's spire to the base and lasers blazed out from all levels leaving the crowds awestruck. The height was disclosed in arithmetic progression, with the numbers being flashed onto the screen, one after another. The tower's height breaks all existing world records for tall buildings. Burj Khalifa is the tallest building in the world according to the three main criteria of the Council on Tall Buildings