Burj Khalifa officially opened on this day in 2010 - a 2,716 ft 6 in (828 metre) wonder of engineering. This is the story behind the world's tallest building. | Guinness World Records

The Burj Khalifa, a skyscraper in Dubai, is the tallest building in the world, which could result in some very long elevator rides. To move people up and down more quickly and efficiently, the building's engineers drew inspiration from urban transit systems. Superstructures: Engineering Marvels is now streaming on Disney | National Geographic Science