The undulating plateau of the Plain of Jars covers an area of 1000 sq km in Xieng Khouang Province. In total there are 136 archaeological sites here, containing thousands of jars, discs and deliberately placed stones. The jars are interesting by dint of their very oddness: as if a band of carousing giants had been suddenly interrupted, casting the jars across the plain in their hurry to leave.

Most of the jars are generally between 1 m and 2.5 m high, around 1 m in diameter and weigh about the same as three small cars. The largest are about 3 m tall. The jars have long left generations of archaeologists nonplussed by how they got there and what they were used for. Local legend relates that King Khoon Chuong and his troops from Southern China threw a stupendous party after their victory over the wicked Chao Angka and had the jars made to brew outrageous quantities of lao-lao. However, it is more likely that the jars are in fact 2000-year-old stone funeral urns. Tools, bronze ornaments, ceramics and other objects have been found in the jars, indicating that a civilized society was responsible for them but no-one has a clue which one, as the artifacts bear no relation to those left behind by other ancient Indochinese civilizations.