The hills around Phonsavan in central Laos are littered with giant stone jars of unknown ancient origin. The area was also the target of intense carpet bombing during the Vietnam War. As a result, only 9 of the 90 recorded jar sites have been cleared of unexploded ordinance, and only three of those are regular stops on the main tourist circuit. They are, creatively enough, known as Jar Sites 1, 2, and 3!
Visiting the Plain of Jars sites isn't always an easy task, but it's well worth the effort! Dirt paths and rice paddies turn to mud on rainy days, but they also offer some spectacular views as you make your way to the jars.
Archeologists estimate that the jars date from 500 B.C. to 200 A.D. One theory suggests that they may have been used in eleborate burial ceremonies. No one knows for sure, though, why they're scattered across the hills, let alone who put them there in the first place.