Dubai's breakthrough building is the Burj Khalifa, which at 829.8 m is the tallest building in the world. For most visitors a trip to the observation deck on the 124th floor here is a must-do while in the city. The views across the city skyline from this bird's-eye perspective are simply staggering. The slick observation deck experience includes a multi-media presentation on both Dubai and the building of the Burj Khalifa (completed in 2010) before a high-speed elevator whizzes you up to the observation deck for those 360-degree views out across the skyscrapers to the desert on one side and the ocean on the other. Night-time visits are particularly popular with photographers due to Dubai's famous city-lights panoramas.<br /> <br /> Back on the ground, wrapping around the Burj Khalifa, are the building's beautifully designed gardens with winding walkways. There are plenty of water features including the Dubai Fountain, the world's tallest performing fountain, modeled on Las Vegas' famous Fountains of Bellagio.