The world's largest swimming pool is located at San Alfonso del Mar resort in Algarrobo, Chile (90 kilometers from Santiago). At the time of its completion in 2006, it was in the Guinness Book of World Records for the largest pool in the world by area.
This impressive saltwater lagoon is the length of over nine football fields, which is more than a kilometer in length, and holds some 250 million liters (66 million US gallons) of water -- the equivalent of 6,000 standard sized pools. There is no hotel at the premises, just apartments to rent from owners. The pool is for residents only but you will have access to the pool if you rent apartment.
During summer, the lagoon maintains a pleasant water temperature that borders 26 degrees Celsius (nine degrees warmer than the nearby sea temperature), and it uses filtered and treated sea water (pumped from the adjacent Pacific Ocean). It's waters are clear with the transparency and intense turquoise color of tropical seas, clean and shark free so you can enjoy your kayak or sail a small boat.
NOTE: The large pool is only for kayak or boat use and water sports, not for swim. You can use smaller pools to swim. Find out more...
~ Pablo Neruda