The first time Sousath Phetrasy saw the huge stone jars scattered in a grassy field, he was entranced. Carefully avoiding old unexploded bombs in the ground, the Laotian businessman walked among hundreds of the ancient, lichen-covered containers, each one large enough to hold a person. The biggest weighed more than 6 tons. From that moment in 1990, the jars became his obsession. He quit his state job and moved to northern Laos to be near them. Over the next seven years, he spent his spare time clearing unexploded bombs, grenades and mortar shells -- leftovers from the United States' 1960s-era "secret war" in Laos -- from three jar fields. His only tools were an old metal detector and a long knife. "I wanted to open the mysteries of the jars, the power of the jars, and let people feel that they have come to a holy place," said Sousath, now 43 and the owner of a tourist hotel. "This is the brother of Stonehenge and Easter Island." Perhaps 2,000 years old, the relics on the plateau known as the Plain of Jars are one of the oldest -- and unexplained -- archeological wonders of Southeast Asia. They have survived looters, the elements and American bombs, but for decades were largely forgotten in the chaos and conflict that swept Laos. Archeologists say there are thousands of jars in this part of northern Laos. The believe that the jars were used to hold bodies for months or years while the remains decomposed. The bones were later removed, cleaned and buried or, in some cases, cremated. Known as secondary burial, the practice is typical of the Bronze and Iron ages and still occurs in the region.