It consists of thousands of stone jars scattered around the upland valleys and the lower foothills of the central plain of the Xiangkhoang Plateau.

Excavation by Lao and Japanese archaeologists in the intervening years has supported this interpretation with the discovery of human remains, burial goods and ceramics around the jars.

[2] The jars at Site 1 (using detrital zircon geochronology) were determined to have been transported to their current location from a presumed quarry eight kilometers away.

The Chinese paintings, which depict large full-frontal images of humans with arms raised and knees bent, date to 500 BC–200 AD.

The discs, which differ from the lids, have at least one flat side and are grave markers which were placed on the surface to cover or mark a burial pit.

The jars lie in clusters on the lower foothills and ridges of the hills surrounding the central plateau and upland valleys.

French geologist and amateur archaeologist Madeleine Colani excavated inside the cave in the early 1930s and found material to support a crematorium theory.

Inside the jars she found, embedded in black organic soil, coloured glass beads and burnt teeth and bone fragments, sometimes from more than one individual.

No further archaeological research was conducted until November 1994, when Professor Eiji Nitta of Kagoshima University and Lao archaeologist Thongsa Sayavongkhamdy surveyed and mapped Site 1.

He dated the Plain of Jars to the late second or early first millennium BC based on the burial urn and associated grave goods.

The suggestion that the jars, as in traditional Southeast Asian royal mortuary practices, functioned as "distilling vessels", was put forward by R. Engelhardt and P. Rogers in 2001.

In contemporary funerary practices followed by Thai, Cambodian, and Laotian royalty, the corpse of the deceased is placed into an urn during the early stages of the funeral rites, at which time the soul of deceased is believed to be undergoing gradual transformation from the earthly to the spiritual world.

She assumed that salt was a commodity sought after by the Plain of Jars people, which brought traders to the Xiangkhouang Plateau.

History has shown that Xiangkhouang, at the northern end of the Annamite Range, provides relative easy passage from the north and east to the south and west.

Lao legends tell of a race of giants who inhabited the area and were ruled by a king named Khun Cheung who fought a long and ultimately victorious battle against an enemy.

Another local story states that the jars were molded from natural materials including clay, sand, sugar, and animal products in a type of stone mix.