The HSBC Rain Vortex at Jewel Changi Airport is the world's tallest indoor waterfall, standing 40 meters high. Designed by architect Moshe Safdie, the waterfall is the centerpiece of a massive glass-and-steel dome filled with a tropical forest. During Singapore's frequent thunderstorms, the waterfall harvests recirculated rainwater that falls through the center of the roof at a rate of 10,000 gallons per minute. The water cools the interior air naturally through evaporation, significantly reducing the building's energy consumption. At night, the circular curtain of water serves as a 360-degree projection screen for light and sound shows. The water is stored in a massive 500,000-liter tank hidden beneath the floor and is continuously filtered and reused.