The enormous pool, which opened in December 2006 at the San Alfonso del Mar resort in Chile after nearly five years of construction work, is said to have set developers back by as much as 1billion pounds.
And on top of the staggering initial cost, it takes requires a further 2million pounds a year in maintenance.
The enormous man-made lagoon is set halfway up the country’s Pacific coast, in the city of Algarrobo, is three fifths of a mile long and is filled with 66 million gallons of crystal clear seawater, a major newspaper reported.
It uses a computer-controlled suction and filtration system to suck water in from the ocean at one end and pump it out at the other, while the sun warms it to 26C - nine degrees higher than the sea.
The record-breaking dimensions mean visitors can paddle or sail their way around the pool instead of swimming.
It is also the world’s deepest swimming pool at 115ft.
The pool’s incredible dimensions leave the next biggest floundering in its wake, with the Orthlieb in Morocco measuring a mere 1,575ft long.