The Largest Man Made Saltwater Lagoon

This man-made saltwater lagoon has been attracting huge crowds to the San Alfonso del Mar resort at Algarrobo, on Chile's southern coast.It is more than 1,000 yards long, covers 20 acres, had a 115ft deep end and holds 66 million gallons of water. This one took five years to build, cost nearly £ 1billion and the annual maintenance bill will be £ 2million. Its turquoise waters are so crystal clear that you can see the bottom even in the deep end. This 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 26 degree Centigrade, nine degrees warmer than the adjoining sea.