The previous largest pool in the world

The swimming pool at the resort of San Alfonso del Mar in Algarrobo city measures 1,013 metres (3,323 ft) in length, covers an area of eight hectares (20 acres), contains 250,000 cubic meters of water and is navigable in small boats. [Xinhuanet]

The previous largest pool in the world is the Orthlieb pool in Casablanca, Morocco, which measures at 480×75 metres. An Olympic size pool is just 50×25 metres.