The world largest pool record in Guinness World Record belongs to the vast pool beside the sea at the San Alfonso Del Mar resort in Chile where it covers more than 20 acres
and clear water transparent to a depth of 35 meters and holds 66 million gallons of water.

Roughly equivalent to about 6,000 standard backyard pools, it took 5 years to build and cost nearly USD 2 billion and the annual maintenance is USD 4 million.