The South Pacific island nation of Vanuatu broke into the headlines a few years ago when the Happy Planet Index ranked it the happiest nation on earth. With beaches like this, how could locals not be euphoric? The crescent of sand at Champagne Beach looks upon a lagoon fringed with coral. The beach gets its name from a phenomenon witnessed by the first travelers to the region -- the shallow waters appear to fizz at low tide, as if the beach is swimming in bubbly. In truth, the effect is caused by gas escaping from volcanic rocks on the sea floor.