3. World's largest swimming pool - San Alfonso Del Mar, Chile

This new resort about 60 miles west of Santiago has been recognized as having the world's largest crystalline pool by the Guinness World Records judges. It's actually a saltwater lagoon that runs for over a full kilometer between the ocean and many apartment buildings that is under completion and covers 20 acres. It is 115 feet deep at one end, and holds 66 million gallons of water, which is about 100 times as much as a typical Olympic size pool.