Enough to make your head swim: World's largest pool which holds 66m gallons is so big you can even sail boats on it

The Crystal Lagoon at San Alfonso del Mar resort, Chile, is large enough for sailing and comes with its own fake beach




At the San Alfonso del Mar resort in Chile, a quick dip could well turn into a marathon.

Swimming a length in this, the world's largest outdoor pool, would mean stroke after stroke for more than three fifths of a mile - that's 20 Olympic-size swimming pools.



The enormous man-made lagoon is set halfway up the country's Pacific coast, in the city of Algarrobo, and is filled with 66 million gallons of crystal clear seawater.

A little slice of the Pacific: The world's biggest pool is three fifths of a mile long and draws water from the ocean, cleaning it and allowing the sun to warm it to 26C

CRYSTAL LAGOON IN NUMBERS

Capacity: 66 million gallons

Length:3,323ft

Area: 20 acres

Temperature: heated to 26C



Estimated cost of construction: £2million

Construction time: Almost five years



Completed: December 2006

The competition: More than twice the length of the next biggest outdoor pool



The pool opened in December 2006 after nearly five years of construction work and is said to have set developers back £2million.

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 pool's incredible dimensions leave the next biggest floundering in its wake, with the Orthlieb in Morocco measuring a mere 1,575ft long.