The Plain of Jars: A Megalithic Archaeological Mystery in Laos

April 29th, 2021

Awake Goy

The Plain of Jars on the Xieng Khouang plain of Laos is one of the most enigmatic archaeological points of interest on Earth. The unusual scattering of thousands of megalithic jars across nearly one hundred sites deep in the mountains of northern Laos has fascinated archaeologists and scientists ever since their discovery in the 1930s.

A New Date for the Plain of Jars

The Plain of Jars is made up of at least 3,000 giant stone jars up to three meters (9.8 feet) tall. Until recently, the Plain of Jars was believed to date to the Iron Age (500 BC to 500 AD). However, a new study published in the journal PLOS One reveals that some of the massive jars could be more than 3,000 years old.

The research also shows that the human burials were interred in the ground beside the jars between 700 and 1,200 years ago. As the researchers state, these new dates for the unusual site known as the Plain of Jars demonstrate that it was “important for a very long time.”

New research shows the human remains were interred beside the jars between 700 and 1,200 years ago. ( Shewan et al. 2021/PLOS ONE )

These results come from Optically Stimulated Luminescence (OSL) dating, which was used on the jars, and radiocarbon dating, which pinpointed the age of the skeletal remains and charcoal samples. In their paper, the researchers write that these dates show “the sites have maintained ritual significance from the period of their initial placement until historic times.”

Most of the megalithic jars are made of sandstone but there are others carved out of much harder granite and limestone. One of the big mysteries about the site is how the massive jars, some weighing up to 10 metric tons, were dragged from the quarry to be placed in groupings up to 10 km (6.2 miles) away. In the recent study, the researchers touched on this conundrum, writing, “Whether the completed jars were dragged on some form of wooden rollers or sledge remains speculative.”

View of megalithic jars at Site 52 of the Plain of Jars. ( Shewan et al. 2021/PLOS ONE )

How Were the Jars Constructed?

Because most of the jars have lip rims, it is presumed that all of them were originally covered with lids. And although a few stone lids have been recorded, it is more likely that the main material used for the coverings was wood or rattan .

Is this a stone lid for one of the massive jars? ( cornfield /Adobe Stock)

The jars appear to 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 them, although no conclusive evidence for this exists. Little is known about the people who carved the huge containers, and the jars themselves give little clue as to their origins or purpose.

According to local legend, the jars were created by a race of giants , whose king needed somewhere to store his rice wine. The wine was to be consumed at a great feast to celebrate an illustrious military victory thousands of years ago.

Laos, Plain of Jars with Hmong girls. (Oliver Spalt/ CC BY SA 2.5 )

Legend tells of an evil king, named Chao Angka, who oppressed his people so terribly that they appealed to a good king to the north, named Khun Jeuam, to liberate them. Khun Jeuam and his army came, and after waging a huge battle on the plain, they defeated Chao Angka.

One Explanation – Catching Rainwater

Some specialists claim that the effort required to have made so many jars suggests they were designed to capture rainwater during monsoon season and later boiling it for use by caravans passing through the region.

Plain of Jars, Phonsavan, Xieng Khuang province, Laos. ( flu4022 /Adobe Stock)

The Plain of Jars as an Extensive Burial Site

That is one alternative, however most archaeologists believe that the jars were used as funerary urns . Excavations have supported this interpretation with the discovery of human remains, burial goods, and ceramics around the stone jars.

It is believed that the jars were used to place the corpses of deceased people – they were left inside the jars to decompose or ‘distill’, a practice that has been common in Thailand and Laos, but usually in pits. It is believed that the bodies were left in the jars for the soft tissue to decompose and the body to dry out before being cremated. Once they had been cremated, the ashes would have been returned to the urns, or perhaps buried in a sacred place, freeing the jars for re-use to decompose another body.

A group of stone jars at the Plain of Jars, Thong Hai Hin Site 1, at Thomghaihin near the town of Phonsavan in the province Xieng Khuang in Laos in Southeast Asia. ( cornfield /Adobe Stock)

Other Recent Findings at the Plain of Jars

In 2016, archaeologists Dougald O’Reilly and Nicholas Skopal, from the Australian National University, and colleagues announced their discovery of 15 new sites containing 137 new examples of the more than 1500-year-old massive jars.

The new sites show that the distribution of the jars is wider than previously thought. This research brings the total number of jars to over 400, which strongly suggests to the team of archaeologists that “there may be thousands more spread across the entire site”.

Recent digs have also revealed 18 more examples of human remains, of which over 60% were infants or babies. Researchers have also established that almost half of the children had died when they were in early infancy or still fetuses.

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A team of researchers from the University of Melbourne, who excavated a popular part of the Plain of Jars, known as ‘Site 1,’ support the idea of it having been primarily used for burial practices. Lead author Louise Shewan told IFL Science that “Site 1 contained three types of mortuary ritual practices: secondary burial of human bone, secondary burial of human remains in buried ceramic jars , and for the first time, a primary burial of two individuals”.

Speaking on the diversity of burial styles, Dougald O’Reilly said: “Our research, while in preliminary stages, has revealed a wide range of mortuary practices . Such diversity of practice in disposal of the dead is uncommon in one culture… there may be several explanations for this diversity and we hope to establish why this is the case.”

Researchers have also found beautifully-carved discs with geometrical images of concentric circles, human figures, and animals, all of which were discovered buried with their decorated sides positioned face-down. Some researchers claim they are probably burial markers . However, as noted above, most of the human deposits were made much later than the jars were created.

Mystery of the Plain of Jars, Phonsavan, Laos, Southeast Asia . ( samantoniophoto /Adobe Stock)

Very Real Dangers at the Plain of Jars

There are still many mysteries surrounding the Plain of Jars, but unfortunately archaeological work is slowed by the fact that this is one of the most dangerous archaeological sites in the world.

There are literally thousands of tons of unexploded bombs, land mines, and other unexploded military ordnance scattered over the plains. These munitions contaminate more than 35% of the province’s total land area and continue to threaten the lives of the 200,000 people who now live in Xieng Khouang.