Marina Bay Sands' 150-meter infinity pool is the world’s largest outdoor pool at that height. At sunset, it is also one of the most beautiful spots on earth.

Mark Chesnut at Orbitz Blog: Not all hotel swimming pools are created equal. Some exude a decidedly cool ambiance. Some have great views. While others are architectural wonders, where swimming seems almost like a gravity-defying act…. For some of the most exciting hotel pool experiences, head across the Pacific. In China, you can swim laps at the Holiday Inn Shanghai Pudong, in a rooftop pool that extends beyond the building itself, with a glass bottom providing dramatic views below. And guests at the Marina Bay Sands, a 2,500-room property in Singapore, can make use of the Sands SkyPark, an oasis that stretches across three 55-story towers, with an infinity swimming pool that’s billed as the world’s largest outdoor pool at that height—or, perhaps we should say, altitude.