Tomorrow Square also known as JW Marriott Hotel is the fifth tallest building in Shanghai, China. It is located in the Puxi district, close to People's Square. It is about 934 ft tall and has 55 floors. This multi-purpose building contains a 342-room Marriott hotel, and 255 executive apartment units. It was completed on 1 October 2003. Starting from a square base, the all-concrete Tomorrow Square tower transforms itself into a diagonal square as it rises to a peak. Engineers of the exterior vertical support system were faced with a unique challenge as a result of this unusual shape. They chose flat slabs for the hotel floors and beam and slab construction for the office floors. A combination of sheer walls and frame action stabilizes the slender tower laterally against wind and earthquake forces. The foundations are 80-metre-long bored piles supporting a column mat.