San Alfonso del Mar, Algarrobo, Chile

Seeing as San Alfonso del Mar fronts a huge beach and the Pacific Ocean, it seems an odd spot for the world's largest swimming pool. But the pool's remarkable spaciousness complements the ocean beyond rather effortlessly, and jumping in the pool's 79 degree water is a much more tempting prospect than venturing into the 63 degree seawater nearby, with its dangerous waves and currents. The resort complex on Chile's central coast resembles a modern Mayan city, with pyramidlike apartment buildings towering above the colossal saltwater pool. Well, since it's over half a mile long and holds about 66 million gallons of water, it's more like a lake. Lining the pool are white-sand beaches, palm trees, and docks for the sailboats that ply the gin-clear water.

Beyond the beach: With such a large pool to get around, it's definitely easiest to stay directly at the resort. If the mammoth lagoon doesn't keep you occupied, there's scuba diving, golf, tennis, paragliding, soccer fields, volleyball courts, a 3-D golf simulator, a full gym, a club, an open-air amphitheater, cafés, ice-cream parlors, tea shops, and an aquarium. Let's just say you won't be bored here.

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