Already drawing the crowds in the South American resort of San Alfonso del Mar in Chile, this artificial lagoon and swimming pool is eight hectares in size and contains an incredible 250,000 cubic meters of water.

Acknowledged by Guinness World Records as being the world’s largest swimming pool, the lagoon trounces all other record holders in the category, including the Orthlieb pool in Casablanca, Morocco, itself a huge 150 meters by 100 meters – the San Alfonso pool is 1km in length. The revolutionary clear water artificial lagoons, transparent to a depth of 35 meters and unprecedented in design and construction methods, are the brainchild of Crystal Lagoons founder, biochemist and Chilean businessman Fernando Fischmann. Equivalent in size to an incredible 6,000 standard domestic pools, details of its technology are to be unveiled for the first time at Cityscape Dubai later this month.

But if you fancy splashing out on one of your own - and you have the space to accommodate it - then beware: This one took five years to build, cost nearly $1billion and the annual maintenance bill will be $2million.

The man-made saltwater lagoon has been attracting huge crowds to the San Alfonso del Mar resort at Algarrobo, on Chile's southern coast, since it opened last month.

Its turquoise waters are so crystal clear that you can see the bottom even in the deep end.

It dwarfs the world's second biggest pool, the Orthlieb -- nicknamed the Big Splash -- in Morocco, which is a mere 150 yards long and 100 yards wide. An Olympic size pool measures some 50 yards by 25 yards.

Chile 's monster pool uses a computer-controlled suction and filtration system to keep fresh seawater in permanent circulation, drawing it in from the ocean at one end and pumping it out at the other.

The sun warms the water to 26c, nine degrees warmer than the adjoining sea.

Chilean biochemist Fernando Fischmann, whose Crystal Lagoons Corporation designed the pool, said advanced engineering meant his company could build 'an impressive artifici al paradise' even in inhospitable areas. 'As long as we have access to unlimited seawater, we can make it work, and it causes no damage to the ocean.'