The Plain of Jars is an area of northern Laos scattered with huge stone jars, 1-3m tall. These mysterious megaliths, found in isolation and in clusters of up to 400, have been the subject of study since the 19th century, but recent work has produced new evidence about when they were placed in the landscape.
Investigations between 2016 and 2019 (see CWA 102) focused on three of the 11 jar-sites that were inscribed on the UNESCO World Heritage list in 2019. During this research, human burials were unearthed at Site 1, along with similar evidence for burial markers at the other two sites (Site 2 and Site 52), which indicates that human remains were probably once present there as well, although none were encountered during excavation. The burials found at Site 1 were dated to the 9th-13th century AD using radiocarbon analysis of the skeletal remains and associated charcoal samples; however, these discoveries raised further questions about when the jars were placed at these sites and how they relate to the burials. Analysis presented in a paper in PLoS ONE is shedding new light on these subjects.
Radiocarbon dating of charcoal from beneath one of the jars at Site 2 and optically stimulated luminescence (OSL) dating of samples from beneath two other jars at the same site strongly suggest that the megalithic jars were placed here well before much of the mortuary activity took place, perhaps as early as the late 2nd millennium BC, as the OSL dates indicate that the original placement of the jars occurred between 1240 BC and 660 BC.
Analysis of one skull fragment from Site 1 (found during excavations conducted in the 1990s) produced a much earlier date than other burials in the region (2282-1265 BC), possibly indicating that burials were taking place at the jar-sites from as far back as this. However, it is evident that the sites were reused over time, well into the historic period, and had retained some kind of ritual significance when the later burials took place in the 9th-13th century AD. Despite this clear, lasting cultural importance, the original function and meaning of the jars remains unknown for now.
Find out more about the project at https://plain-of-jars.org.