Jewel Changi Airport
The Rain Vortex, sponsored as the HSBC Rain Vortex, is the world's largest and tallest indoor waterfall, standing at  high. Recirculating rain water is pumped to the roof to free fall through a round hole at up to  per minute to a basement-level pool. An acrylic funnel at the bottom prevents splashing and insulates the sound of the cascade. The toroid-shaped roof has more than 9,000 pieces of glass spanning  with a sloped oculus as the mouth of the waterfall acting as "a continuation of the building...completed in a liquid form." At night, the circular walls of the waterfall becomes a 360-degree stage for a light-and-sound show.