San Alfonso del Mar is a private resort in Algarrobo, Valparaiso in Chile, about 100 km west of Santiago. The resort has one of the world's largest swimming pools. It is the largest swimming pool in South America 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.
The pool is 1,013 m (3,323 feet) long covering 8 ha (20 acres) containing some 250 million liters (66 million US gallons)[4] of seawater, with a maximum depth of 3.5 m (11.5 feet). The water is pumped from the adjacent Pacific Ocean, then filtered and treated. Access to the pool is limited to resort residents only..