Jewel Changi Airport

More destination than airport mall, Jewel is a glass-and-steel dome by architect Moshe Safdie that fuses nature, shopping and play. At its heart, the seven-storey HSBC Rain Vortex — the world's tallest indoor waterfall — pours from the roof through a ring of terraced rainforest, the Shiseido Forest Valley. Up top, Canopy Park adds hedge mazes, mirror mazes and bouncing sky nets; below sprawl some 280 shops and eateries. It's free to wander and a brilliant way to fill a layover, but also a genuine outing for locals. Visit after dark for the waterfall's hourly light-and-sound show.