In a remote corner of northeastern Laos, far from the well-trodden backpacking trail, a strange sight lurks in Southeast Asia’s Annamite Mountains. Across hundreds of square miles of hilly terrain, thousands of mysterious stone containers have been scattered. Clearly, they are ancient in origin, but who created them, and why? This is the Plain of Jars — one of the weirdest and most treacherous landmarks on Earth.
Ever since archaeologists first began studying this area in the 1920s, the Plain of Jars has puzzled experts around the world. Believed to date as far back as 500 B.C., these bizarre artifacts vary greatly in size and shape, with some up to nine feet tall. And with the heaviest weighing in at a staggering 14 tons, their construction must have been no easy task.
Obviously, these containers had some deep significance for the ancient people who built them — although exactly what remains a matter of some debate. But it’s not just the mystery surrounding the Plain of Jars that makes it a fascinating location. For decades, research in the region has been thwarted by the realities of Laos’ horrific past.
For nine years, the United States waged a secret war against communists in Laos, barraging the country by dropping an astonishing 270 million bombs. And even now, almost 50 years later, the landscape remains littered with unexploded ordnance. For archaeologists keen on studying the Plain of Jars, it’s a dangerous — and potentially deadly — job.
Despite the hazards, however, a succession of brave researchers have traveled to this spot on the Xiangkhoang Plateau, some 220 miles north of Laos’ capital of Vientiane. Treading carefully, they have begun to uncover the truth about the Plain of Jars. And as it turns out, these artifacts have been hiding a rather macabre secret.
The Xiangkhoang Plateau covers a vast area in the north of Laos, bordered by the Annamite Mountains in the east and the Luang Prabang Range in the west. And in the center of this region sits the Plain of Jars, which — despite its name — is actually a region of valleys and hills.
Today, the Plain of Jars is gradually becoming a tourist destination, and operators are beginning to offer guided visits to this remote part of the Xiangkhoang Plateau. Nevertheless, the roads are still makeshift and winding, and a trip to see these ancient artifacts remains something of an adventure.
On arrival at the site, visitors are greeted by an extraordinary spectacle: over 2,100 mysterious jars, all scattered across the landscape. While some of them are plain, others have been carved with designs depicting human faces and figures. According to experts, most of the containers are hewn from sandstone, although some have been crafted from other materials such as coral and granite.
Alongside the containers that litter the plain are a number of discs also carved from stone. Did these once function as lids to seal up whatever was kept inside the jars? Currently, experts are unsure — although many theories have emerged surrounding these mysterious objects and their purpose in this far-flung place.
According to experts, the oldest of these containers dates back to around 500 B.C., while the earliest were forged around 1,000 years later. Technically, this means that they were the product of an Iron Age civilization. But unlike some other contemporary cultures, little is known about the people who carved these mysterious jars.
Archaeological investigations at the Plain of Jars began in the early 20th century, when the French colonialists arrived in Laos. And from that point onwards, the mystery began to slowly unravel. According to one researcher, Henri Parmentier, the containers were filled with artifacts that could shed light on their purpose.
During the 1920s, Parmentier recorded all sorts of items present at the Plain of the Jars, including human bones, weapons, jewelry and beads. However, it wasn’t until the following decade that the investigation really got underway. Beginning in the early 1930s, French archaeologist Madeleine Colani conducted the first thorough field study of the site.
Even today, much of what we know about the jars and the people who built them comes from Colani and her work. For example, she was the first archaeologist to determine that the containers had not been carved in situ. In fact, they were created using stone from miles away. How they got there, then, remains another enduring mystery of this strange site.
Although Colani speculated that Laos’ Iron Age inhabitants may have used tree trunks to move the jars into place, this has yet to be proven. Meanwhile, over the years, the French researcher honed some solid theories about the purpose of the containers. But decades later, even these are still up for debate.
In 1935 Colani published The Megaliths of Upper Laos, and over 80 years later it remains the most authoritative source concerning the Plain of Jars. But before other researchers could take up the mantle, the shadow of war fell over Laos. And for decades, unrest in the region put a stop to any archaeological studies.
For most of World War II, Laos was occupied by the Japanese, a move that set the wheels in motion for the independence movement. Eventually, in 1954, the country was finally granted autonomy. By that time, however, the Axis powers had been replaced by a different threat, and much of the world was caught in the crossfires of the Cold War.
Although Laos was officially neutral during the Cold War, it had the misfortune of sharing a border with Vietnam. And before long, the U.S. fight against communism had arrived in South East Asia. In November 1955, a long and bloody conflict broke out that would rage for the next 20 years.
For decades, the Soviet-backed communist forces of North Vietnam fought against the American-allied South Vietnamese. But as that conflict escalated, it began to spill over into neighboring countries. In Laos, for instance, another communist movement was rising, and the U.S. soon took steps to put it down.
In 1959, the Laotian government went to war against members of Pathet Lao — a communist group closely linked to North Vietnam. And within a few years, the U.S. was also lending its support to this conflict across the border. But the response was heavy-handed and brutal, kickstarting a campaign of terror that, in some ways, continues to this day.
While backing the Laotian government in their fight against Pathet Lao, the U.S. flew 580,944 separate bombing missions between 1964 and 1973. And over the course of those nine years, they dropped over two million tons of ordnance on the South East Asian country. Shockingly, that’s the equivalent of one plane-load of munitions every eight minutes — for almost a decade.
Known today as the “Secret War,” it was a horrific period in history that resulted in the loss of thousands of lives. And even today, Laos is considered more heavily bombed, per capita, than any other country on the planet. Sadly, once the violence finally stopped, the danger was far from over.
According to reports, some 30 percent of the U.S. bombs that were dropped on Laos failed to explode on impact. So, even after the war drew to a close, there were parts of the country that remained incredibly dangerous. Take Xieng Khouang Province, for example, home to the Plain of Jars.
Throughout the conflict, Xieng Khouang Province was among the most bombed regions in Laos, the target of some 63,000 attacks. And by the time that research work resumed in the 1990s, the area was still carpeted in unexploded bombs. For archaeologists, this volatile environment has posed a unique challenge.
Beginning in 2004 the British organization Mines Advisory Group, or MAG, started clearing unexploded bombs from Xieng Khouang Province. However, it wasn’t just ordnance that they uncovered. In an unprecedented partnership, they invited archaeologists from the United Nations Educational, Scientific and Cultural Organisation, or UNESCO, to work in conjunction with the clearance teams.
Thanks to the work of groups such as MAG, archaeology in Xieng Khouang Province is becoming a safer task. But even though the Plain of Jars is now an emerging tourist destination, the threat of unexploded bombs remains. Meanwhile, in 2019, the location was listed as a UNESCO World Heritage Site, ensuring its future conservation.
So what exactly is it about the Plain of Jars that has persuaded archaeologists to brave such unforgiving conditions over the years? Since the 1930s, a number of different theories have emerged in an attempt to explain the strange containers. But are we any closer to knowing the truth?
Locally, the people who are familiar with the Plain of Jars have their own legends about who constructed the mysterious objects. According to these stories, the region was once home to a race of giants ruled by a king named Khun Cheung. One day, it’s said, this great leader wished to celebrate a victory against his enemies and the end of a great battle.
In order to celebrate, the legend explains, Khun Cheung decided to brew a vast amount of alcohol. And in order to do so, he instructed his people to forge a number of giant containers. For years, this story has been given a degree of credence by the presence of a kiln-like cave in one section of the Plain of Jars.
According to some locals, then, the jars were not carved from stone. Instead, some believe, they were crafted from a mixture of clay, sugar, sand and animal products, before being fired in the kiln. These days, however, it is generally accepted that the containers were hewn from pieces of rock and relocated to the plain.
But if that is how the jars were made, are we any closer to understanding why? One theory to explain their presence on the Xiangkhoang Plateau is that they were intended to collect rainwater. Apparently, at certain times of the year the region would dry up, presenting a challenge to travelers crossing the terrain.
According to this theory, the containers would have been placed across the Plain of Jars, giving caravans year-round access to water. And although it would not have been safe to drink, travelers could easily have boiled the liquid to remove any impurities. But is this just a theory, or has any evidence been uncovered to support this claim?
As early as the 1920s, archaeologists discovered that many of the jars contained beads crafted from materials such as carnelian and glass. According to some, this could be evidence that the Iron Age inhabitants of the Xiangkhoang Plateau were leaving gifts and offerings in the hope of encouraging rain. However, it is also possible that the artifacts found their way into the containers by other means.
Meanwhile, another theory claims that the jars were used as a way of storing food. But by far the most popular hypothesis is also the most gruesome: that the containers were linked to Iron Age mortuary practices. In short, these strange artifacts were where the ancient Laotians chose to dispose of their dead.
This explanation was first suggested by the work of Parmentier, who frequently recovered fragments of human bone at the site. And later, after spending months studying the mysterious objects, Colani also posited that the jars could have been used in connection with funeral rites. Specifically, that they were designed to hold human remains that had been cremated.
Before this theory could be explored any further, work at the site was disrupted by the war. But when UNESCO archaeologists returned to the Plain of Jars in 2004, they discovered plenty of evidence to support Colani’s theory. At one point, they had recovered almost 90 bags of artifacts from the site, including pieces of human bone.
In a 2004 interview with British newspaper The Telegraph, Belgian consultant Julie van den Bergh explained that the jars were “most likely burial related, or used to decompose the corpse.” Additionally, she was excited to announce the discovery of charcoal at the site, as it could be used to date the Plain of Jars with more accuracy than before.
Later, in 2019, the results of another study were published in the journal Antiquity. In it, researchers revealed that they had discovered numerous human remains at the site, many of which belonged to infants and children. In fact, they concluded that, in one section of the site, more than 60 percent of the mortuary artifacts came from people under 15 years old.
Among those, it seems, nearly 50 percent were the remains of children that had died in infancy. In the paper, researchers claim that these findings suggest that malnutrition and poor health were pressing issues for the culture that constructed the Plain of Jars. However, they also revealed evidence that the containers may have been in use much more recently than the Iron Age.
In fact, the paper claimed that some of the human remains retrieved from the site could be dated to between the 9th and 13th centuries A.D. However, this does not mean that previous dates for the jars are inaccurate. Rather, it could be evidence that the containers were used for burials long after they were placed on the plain.
Moving forwards, there are still many things to be learned about the Plain of Jars. But with the prospect of tourism rising in the region, steps must be taken to protect the still-volatile site for generations to come. Thanks to UNESCO, a five-year plan has been put in place to further archaeological research and ensure that commercialization of the area serves to benefit the local community.