The remains of an ancient stone jar catch the last rays of...

XIENG KHOUANG, LAOS - 2008/01/19: The remains of an ancient stone jar catch the last rays of the day at Site Two of the Plain of Jars. Many of the massive jars at the site have been inadvertently damaged by locals collecting stones or their cattle rubbing against them over the centuries. Today, the three main sites are fenced off to keep farm animals away and protected by local villagers who see them as a key source of tourist revenue. There are more than 2,000 stone jars scattered around the Plain of Jars and the surrounding mountains. They are up to 2,000 years old, weigh tons apiece and no one knows who built them or why. Today, the jars are a UNESCO World Heritage Site, conveying a degree of protection and fame. And each of the last few years has seen an uptick in the number of foreign visitors to the remote sites.. (Photo by Jerry Redfern/LightRocket via Getty Images)