The mysterious Plain of Jars is an archaeological site in central Laos that has thousands of stone vessels scattered across the ground. Researchers have long tried to figure out why the stone jars were littered across this remote part of Laos.

Archaeologists recently unearthed an ancient burial site and human remains at the Plain of Jars. The burial site is estimated to be 2,500 years old, and could help researchers glean new information about the mysterious site.

The researchers are also using data from the excavations and video from aerial drones to recreate the archaeological site in virtual reality. This means scientists can revisit and review their field work in Laos from more than 4,000 miles away, in Australia. [Read full story about the virtual reality project at the Plain of Jars]

Strange sight

Credit: ANU

An aerial drone photograph of “Jar Site 1” in the Plain of Jars, located near Phonsavan in central Laos.

Uncovering the unknown

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The archaeologists from Laos and Australia spent four weeks in February 2016 mapping and excavating the ground around a group of the massive carved stone jars that dot the landscape at Jar Site 1.

Ancient burial practices

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Jar Site 1 is the best known of more than 85 ancient jar sites in the remote hills and valleys of the Xieng Khouang plateau in Laos.

The area was heavily bombed by American warplanes during the Vietnam War and only seven jar sites, including Site 1, have been cleared of undetonated bombs.

View from above

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An aerial drone photograph of stone jars and marker stones at Jar Site 1.

Expert eyes

Credit: Dougald O’Reilly, ANU

Thonglith Luangkhoth, an archaeologist in Laos, inspects the primary burial site discovered at Jar Site 1.

Looking toward heaven

Credit: Dougald O’Reilly, ANU

This is a view of the primary burial site discovered at Jar Site 1. The quartz-rich stone is aligned so the skull appears to look out through the hole.

Unique memorials?

Credit: Dougald O’Reilly, ANU

The Jar Site 1 site, photographed from one of the excavation trenches.

Teamwork

Credit: Dougald O’Reilly, ANU

Thonglith Luangkhoth (left) and Dougald O’Reilly (far right) excavating a secondary burial site. O’Reilly led a team of scientists on the joint Laos-Australian expedition to the Plain of Jars.

Burial jars

Credit: Dougald O’Reilly, ANU

The researchers also uncovered 11 ceramic jars, which are expected to contain “secondary” burials of human bones from which the flesh was removed. Here, archaeologists at Jar Site 1 record details of the ceramic secondary burial jars.

Exploring an ancient civilization

Credit: Dougald O’Reilly, ANU

Dougald O’Reilly, an archaeologist at the Australian National University, at Jar Site 1 in February 2016.

Excavating the site

Credit: Dougald O’Reilly, ANU

The contents of the ceramic jars excavated from the site will also be carefully examined to confirm if, as the researchers suspect, they hold human remains.

DNA samples

Credit: Shewan & O’Reilly, 2016

Archaeologists Louise Shewan, of Monash University in Melbourne, Australia (center), and Dougald O’Reilly, from Australian National University in Canberra (right), are directing a major five-year investigation of the Plain of Jars site. This photograph shows the researchers removing human teeth from the underside of one of the sandstone disks used to mark some of the ancient graves at Jar Site 1.

Genetic material from the ancient teeth with be used for DNA analysis, while traces of radioactive strontium will be used to identify the geological signature of the area where the people buried here gathered their food.

 

Eyes in the sky

Credit: Shewan & O’Reilly, 2016

The researchers also used aerial drones, like this one, over Jar Site 1 to map the unique landscape of the Plain of Jars to build a virtual reality simulation of the area and to aid ongoing archaeological research.

Aerial footage

Credit: ANU/Plain of Jars Archaeological Project

Aerial footage from the drones has been combined with data from geophysical surveys and ground-penetrating radar to create a 3D virtual replica of Site 1 at the Plain of Jars. The simulation will enable researchers to review and explore the site from the advanced Cave2 virtual reality facility at Monash University in Australia.

Immersive experience

Credit: Plain of Jars Archaeological Project /MIVP Cave2

The aerial landscape images and other data from research at the Plain of Jars have been integrated into an advanced 3D simulation at the Cave2 virtual reality facility at Monash University. The simulation lets researchers in Australia view and explore the images and other data from the different research efforts within the Plain of Jars Archeological Project.

Digital records

Credit: Plain of Jars Archaeological Project/MIVP Cave2

The Cave2 simulation also records a timeline that can be stepped forward or back to show the state of the excavations at any time, and which will be updated as the digs and discoveries at the Plain of Jars continue at Site 1 and other jar sites in the years to come.

Seeing through the trees

Credit: Shewan & O’Reilly, 2016

Aerial drones will also be used to map jar sites that are too rugged for traditional archaeological methods, such as Jar Site 52, shown here, which is in broken country covered by trees and bush.

Drones also let the researchers explore some of the many jar sites where undetonated cluster bombs left over from the bombardment of Laos during the Vietnam War make it too dangerous to dig.

Origin of the stones

Credit: Shewan & O’Reilly, 2016

Richard Armstrong, an archaeologist and geochemist at Australian National University, is leading research to learn more about the origins of the stone jars themselves, using uranium-lead dating on traces of the mineral zircon in the rocks the jars were quarried from. This information will give accurate ages for the stone jars, and help to date the quarries where they were made.

Recording history

Credit: ANU/Plain of Jars Archaeological Project

The researchers say the virtual simulation of the Plain of Jars will serve as a digital record of scholarship about the Plain of Jars as their investigations continue. It will also be used to support the designation of the Plain of Jars as a UNESCO World Heritage site, which the Laos government hopes will stimulate tourism and further scientific research in the region.