According to Atlas Obscura, the urns could be as much as 2,000 years old and each can weigh up to 14 tons. The most prominent theories center around death, given that human bones were found in the area. Many believe the urns to be burial jars or used in funeral rites, while others believe they were simply used as food storage. Local Laotian mythology states that jars were used to brew rice wine in celebration of a victory by a legendary king of giants.
The jars only received western attention in the 1930s, when French archaeologist Madeleine Colani visited the site. It was said the site was used to house jewelry and axes along with other valuables, but everything had been heavily looted by the time she arrived. The Plain of Jars is not the only cluster of these mysterious ancient vessels, as small groups can be found tracing a path all the way to India, suggesting they could be connected to some ancient trade route.
Unfortunately, there is something else that litters the Plain of Jars: bombs. Unexploded bombs from the Secret War of the 1960s make this not only one of the most mysterious ancient sites in the world, but also one of the most dangerous.