The Shanghai Tower is a 632-metre, 128-story megatall skyscraper in Lujiazui, Pudong, Shanghai. As of 2015, it is the world's tallest building, by height to highest usable floor (Level 127, 587.4 m). It also has the world's highest observation deck within a building or structure (Level 121, 561.25 m), and the world's fastest elevators at a top speed of 20.5 m/s. It is the world's second-tallest building by height to architectural top and the world's third-tallest structure.