For over a century, the massive wooden coffins perched on the treacherous cliffs of Northwest Thailand puzzled explorers. Now, ancient DNA has finally revealed the identity of the people who put them there.

The Mystery of the Highlands
Since they were first documented by Western explorers over 100 years ago, the “Log Coffin” culture of Thailand’s Mae Hong Son province has been a source of endless speculation. Found in over 40 cave sites, these giant coffins—some over 10 meters long—were carved from single teak trees and hoisted onto high limestone cliffs or balanced on wooden stilts.

The central question remained: Who were these people, and why did they go to such extreme lengths to bury their dead in places seemingly inaccessible to humans?

The DNA Breakthrough
A massive international genomic study, concluding in early 2026, has finally cracked the case. By analyzing the DNA of 33 individuals buried in these caves, researchers have mapped a complex ancestral web.

The findings reveal that the “Log Coffin” people were not a small, isolated tribe. Instead, they were part of a large-scale migration of farming communities moving south from the Yangtze River valley in present-day China. The genetic markers show a direct link to Austroasiatic and Austronesian-speaking populations, proving that these cliffside cemeteries were the work of a sophisticated, well-connected society.

A Social Network of the Dead
The study also solved the mystery of the coffins’ distribution. Researchers found that people buried in different caves were often closely related. This suggests that the cliffside sites were “family plots” used by specific clans over many generations.

The act of placing coffins on cliffs was likely more than just a way to protect them from scavengers. Archaeologists now believe it was a spiritual statement—positioning the deceased “closer to the heavens” while marking the clan’s territory in the rugged highlands.

Preserving the Legacy
With the mystery of their origins solved, the focus has shifted to preservation. Many of these ancient teak structures, some dating back 2,300 years, are at risk from humidity and tomb raiders.

“Now that we know who they were, we have a responsibility to protect their resting places,” says Dr. Siriamon, a lead archaeologist on the project. “They weren’t just ‘mysterious cliff people’; they were the ancestors of the diverse cultures we see across Southeast Asia today.”