The Biggest/Largest Swimming Pool of the World - South American resort of San Alfonso del Mar in Chile

This swimming pool and artificial lagoon was acknowledged by Guinness World Records as the world's largest swimming pool. It is eight hectares in size and contains 250,000 cubic meters of water. Head down to the South American resort of San Alfonso del Mar in Chile to get your feet wet. 
San Alfonso del Mar is a resort located in Algarrobo, Chile featuring a 1,000m long, 19-acre outdoor pool, 250 million liters of water which holds a Guinness world record as the largest in the world.
Apart from its large size, the lagoon has another spectacular feature: its waters have the transparency and intense turquoise color of tropical seas. This has been made possible thanks to an advanced technology developed by the Chilean company Crystal Lagoons, which uses water pumped from the Pacific Ocean, that is then filtered and treated for supply to the pool, built at the cost of US$3.5 million whilst the maintenance costs are said to be 1/4th of those associated to a pro golf course.