The Plain of Jars is a megalithic archaeological landscape in Laos. Scattered in the landscape of the Xieng Khouang plateau, Xieng Khouang, Lao PDR, are thousands of megalithic jars. These stone jars appear in clusters, ranging from a single or a few to several hundred jars at lower foothills surrounding the central plain and upland valleys.
The Xieng Khouang Plateau is located at the northern end of the Annamese Cordillera, the principal mountain range of Indochina. Initial research of the Plain of Jars in the early 1930s claimed that the stone jars are associated with prehistoric burial practices. 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 stone jars. The Plain of Jars is dated to the Iron Age (500 BCE to 500 CE) and is one of the most fascinating and important sites for studying Southeast Asian prehistory. The Plain of Jars has the potential to shed light on the relationship between increasingly complex societies and megalithic structures and provide insight into social organisation of Iron Age Southeast Asia’s communities. To visit the jar sites one would typically stay in Phonsavan.
The Jar Sites
More than 90 sites are known within the province of Xieng Khouang. Each site ranges from 1 up to 400 stone jars. The jars vary in height and diameter between 1 and 3 metres and are all without exception hewn out of rock. The stone jars are undecorated with the exception of a single jar at Site 1. This jar has a human bas-relief carved on the exterior. Parallels between this ‘frogman’ at Site 1 and the rock painting at Huashan in Guangxi, China have been drawn. The paintings, which depict large full-frontal humans with arms raised and knees bent, are dated to 500 BC – 200 AD .
From the fact that most of the jars have lip rims, it is presumed that all stone jars supported lids, although few stone lids have been recorded; this may suggest that the bulk of lids were fashioned from perishable materials. Stone lids with animal representations have been noticed at few sites such as Ban Phakeo (Site 52). The bas-relief animals are thought to be monkeys, tigers and frogs. No in situ lid has ever been found.
Not to be confused with stone lids are the stone discs. The stone discs have at least one flat side and are grave markers which were placed on the surface to cover or mark a burial pit. These grave markers appear more infrequently than stone jars, but are found in close proximity. Similar are stone grave markers; these stones are unworked, but have been placed intentionally to mark a grave. To the north of Xieng Khouang an extensive network of intentionally placed largely unworked stones marking elaborate burial pits and chambers are known as ‘standing stones of Huaphan’. Following the investigations by Colani, these were dated to the Bronze Age. Material associated with the stone grave markers in Xieng Khouang, however, is similar to the stone jars artefacts.
The jars lie in clusters on the lower footslopes and mountain ridges of the hills surrounding the central plateau and upland valleys. Several quarry sites have been recorded usually close to the jar sites. Five rock types are known:sandstone, granite, conglomerate, limestone and breccia.
The majority of the jars are sandstone and have been manufactured with a degree of knowledge of what materials and techniques were suitable. It is assumed that Plain of Jars’ people used iron chisels to manufacture the jars, although no conclusive evidence for this exists. Regional differences in jar shape have been noted. While the differences in most cases can be attributed to choice and manipulation of rock source, form differences, such as small apertures and apertures on both ends (double holed jars) which would affect the use of the jar, have been recorded in one district only.
The cave at Site 1 is a natural limestone cave with an opening to the northwest and two man-made holes at the top of the cave. These holes are interpreted as chimneys of the crematorium. French geologist and amateur archaeologist Madeleine Colani excavated inside the cave in the early 1930 and found archaeological material to support a centralized crematorium theory. Colani also recorded and excavated at twelve Plain of Jars sites and published two volumes with her findings in 1935.
The material findings and context led her to the interpretation of the Plain of Jars as an Iron Age burial site. Inside the jars, she found embedded in black organic soil coloured glass beads, burnt teeth and bone fragments, sometimes from more than one individual. Around the stone jars, she found human bones, pottery fragments, iron and bronze objects, glass and stone beads, ceramic weights and charcoal. The bone and teeth inside the stone jars show signs of cremation, while the burials surrounding the jars yield unburnt secondary burial bones.
No further archaeological research was conducted until November 1994, when Professor Eiji Nitta of the Kagoshima University in collaboration with Lao Archaeologist Thongsa Sayavongkhamdy surveyed and mapped Site 1. Nitta claims the surrounding burial pits are contemporary to the stone jar, as they are cut into the ancient surface on which the jar was placed. Nitta believes the stone jar was a symbolic monument to mark the surrounding burials.
He dates the Plain of Jars to the late first or early second millennium B.C. based on the burial urn and associated grave goods. Sayavongkhamdy undertook survey and excavation between 1994 and 1996 supported by the Australian National University. Sayavongkhamdy and Bellwood interpret the stone jars as a central single person’s primary or secondary burial, surrounded by secondary burials of family members. Archaeological data collected during UXO clearance operations supervised by UNESCO archaeologist Julie Van Den Bergh at the in 2004-2005 and again in 2007 provided similar archaeological material results. Van Den Bergh recorded similar to Nitta stratigraphical evidence that the stone jars and surrounding burials are contemporary.
The differing burial practices of cremation inside and secondary inhumation surrounding the jar, as noted by Colani, can not easily be explained, in particular as the cremated remains were identified mainly belonging to adolescents and the associated material does not appear to differ greatly from the surrounding burials. While the UXO clearance operations did not include emptying of jars and thus no additional evidence could be gathered, Van Den Bergh claims that the stone jars initially may have been used to distil the dead bodies and that the cremated remains within the stone jars represent the latest phase in Plain of Jars. The stone jars with smaller aperture may reflect the diminishing need to place an entire body inside.
The suggestion that stone jars in a similar fashion as 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 connected to Thai, Cambodian and Laotian royalty, the corpse of the deceased during the early stages of the funeral rites is placed into an urn, while the deceased is undergoing gradual transformation from the earthly to the spiritual world. The ritual decomposition is followed by cremation and secondary burial.
The royal burials are located across watercourses from the habitation areas in a geographically high, prominent area. Meanwhile, it is interesting to note that amongst the Black Thai people who have been in the region at least since the 11th century, the elite are cremated to release their spirit to heaven, while commoners are buried, leaving their spirit to remain on earth. Colani connected the location of the jars sites to ancient trade routes and in particular with the salt trade. He assumed salt was a commodity sought after by the Plain of Jars people, bringing traders to the Xieng Khouang Plateau. The Xieng Khouang area is rich in metallic minerals, mainly due to the granite intrusions and associated hydrothermal activity.
Two principal iron ore deposits exist in Lao and both are in Xieng Khouang. The presence and locations of the numerous jar sites in Xieng Khouang may relate to trading and mining activities. History has also shown that Xieng Khouang at the northern end of the Annamite Range provides relative easy passage from the north and east to the south and west.
Within the geographic setting of Xieng Khouang, the jar sites may reflect a network of intercultural villages, whereby the locations of the jars are associated to long-distance overland routes which connect the Mekong basin and the Gulf of Tonkin System. The jar sites show superficial regional differences such as jar form, material and number of jars per site but share common setting characteristics such as burial practices, elevated locations and commanding views over the surrounding area.
The most investigated and visited Jar site is located close to the town of Phonsavan, and is known as Site 1. Seven jar sites however, have been cleared of UXO (unexploded bombs) and are open to visitors. These are currently most visited Site 1, 2 and 3, and Site 16 near the Old Capital Xieng Khouang, Site 23, near the big hot spring in Muang Kham, Site 25 in the largely unvisited Muang Phukoot district and Site 52, the largest known jar site to date with 392 jars near a traditional Hmong village only accessible on foot.
Legends and Local History
Lao stories and legends tell of a race of giants who inhabited the area ruled by a king called Khun Cheung, who fought a long, eventually victorious battle against his enemy. He allegedly created the jars to brew and store huge amounts of lau hai (“lau” means “alcohol”, “hai” means “jar”—So “lau hai” means rice beer or rice wine in the jars) to celebrate his victory. Another local tradition states the jars were molded, using natural materials such as clay, sand, sugar, and animal products in a type of stone mix. This led the locals to believe the cave at Site 1 was actually a kiln, and that the huge jars were fired there and are not actually of stone.
Another suggested explanation for the jars’ use is to collect monsoon rainwater for caravan travelers along their journey at times when rain may have been seasonal and water was not readily available on the easiest foot paths. Rainwater would then be boiled, even if stagnant, to become potable again, a practice long understood in Eastern Eurasia. The trade caravans that camped around these jars and could have placed beads inside them as an offering, accompanying prayers for rain or they might simply have been unassociated lost items.
Between 1964 and 1973, Laos was subject to the most intense bombing raids ever by US bombers (see Secret War) . In this period, more ordnance was dropped on Laos and particularly on the Plain of Jars, including 260 million cluster bombs, than was dropped during the whole of World War II. 80 million failed to explode and pose a deadly threat to the population to this very day.
The large quantity of UXOs (unexploded ordnance) in the area, especially cluster munitions, limits free movement. All over the plain evidence of the bombing raids can be seen in the form of broken or displaced jars and bomb craters. Sightseeing on the Plain of Jars can only be done on cleared and marked pathways.
The Mines Advisory Group, a non-governmental organization, in collaboration with UNESCO and funded by the New Zealand Government (NZAID) conducted a UXO clearance phase at the three most visited sites from July 2004 until July 2005. A second phase of UXO clearance at the jar sites also funded by NZAID was undertaken in 2007; four more jar sites were made safe.
The Laotian government is considering applying for status as a UNESCO World Heritage site for the Plain of Jars. The UNESCO-Lao Safeguarding the Plain of Jars Project has been an ongoing effort by UNESCO and the Lao Government to document and rehabilitate the Plain of Jars. Clearing of the UXO-hazards is one requirement before the sites can be studied and developed for tourism. Community based involvement in the management and conservation of the jar sites has been one of the main objectives of the project and is proving to be success. Unfortunately, tourism pressure on the main visited sites is the main cause of recent damage to the stone jars.