Burj Khalifa, Dubai, UAE

Until recently called Burj Dubai, at 2,722 feet (828 meters) and 160 floors the Burj Khalifa is the world's tallest structure by a long shot. Already dominating the Dubai skyline, the newly opened tower

houses nine hotels and a Las Vegasinspired fountain system. The visitors' entrance is located at the lower ground floor of Dubai Mall. There is an outdoor observation deck on the 124th floor. Although the observation deck is called At the Top, at 1,483 feet (452 meter) it's just over halfway up the tower itself. Still it is he third-highest observation deck in the world.