The Burj Khalifa is a skyscraper in Dubai. It rises 2717 feet (828m) into the sky. It is the tallest building in the world. The skyscraper has 162 floors allows a 360 degree view of the city. Its construction began in 2004. The costs esceeded $20 billion, and nearly 12,000 people worked on it . The Burj Khalifa the highest mosque (158th floor) and the highest swimming pool (76th floor) in the world. Fireworks and celebrations highlighted the official opening of the building in 2010.