<P> San Alfonso del Mar is a private resort in Algarrobo, Chile, about 100 km (62 mi) west of Santiago . The resort has one of the world's largest swimming pools . At the time of its construction it was the largest . </P> <P> The pool is 1,013 m (3,323 ft) long, covering 8 ha (20 acres), containing some 250 million litres (66 million US gallons) of seawater, with a maximum depth of 11.5 ft (3.5052 m). The water is pumped from the Pacific Ocean, filtered, and treated . Access to the pool is for residents only . There is no hotel at the premises, just apartments . </P> <P> The pool was developed by Fernando Fischmann; his Chilean company Crystal Lagoons built the pool, opening in December 2006 . Early estimates put the total cost of construction at about US $3.5 million for the filtration system alone . </P>

Where is the largest pool in the world located