In the Western Sichuan province, between central China and the Tibetan Autonomous Region, there exist hundreds of mysterious stone towers, some of them over 200 feet tall. They dot the valleys and the foothills of the Himalayas, often clustered near villages where they have been repurposed as stables for yaks and ponies. Others are abandoned and in a state of disrepair; their wooden stairs gone and roof collapsed. Although they clearly exist for centuries, the purpose and origin of these structures remain a mystery, and even the local residents are ignorant of their history

The towers were first brought to the attention of the outside world by French explorer Frederique Darragon, who went to Tibet in 1998 to research snow leopards, but instead fell under the spell of these enigmatic structures. Darragon spent the next five years studying the towers. She counted them, mapped them, photographed them, and even climbed them when possible to collect samples of wood from the beams for analysis. But when she talked to people living in proximity to the towers, she was surprised to learn that nobody knew who built them and for what purpose. A search among the texts in the local Buddhist monasteries was also unfruitful. However, she did find a few references to the towers in some Chinese annals and in the diaries of 19th-century European travelers to the region, but nobody made any attempts to study them or unravel the puzzle.

The lack of local knowledge about the towers’ origin could be due to the region’s history and geography. The region where the towers are found has been historically occupied by different mountain tribes who have maintained isolation for centuries. Due to the diverse nature of their origins and the fragmented terrain in which they live, the languages and dialects they speak are vastly different from one another. “Even from one valley to the next, the locals couldn’t speak to each other,” Darragon says in a documentary titled Secret Towers of the Himalayas, produced by her friend Michel Peissel. Darragon believes that knowledge of the towers might have been previously passed down through oral tradition, but now forgotten as dialects changed or vanished.

Himalayan towers depicted in a painting of the Jinchuan campaigns.

These monumental structures were built using a mixture of cut stone, brick, and timber and come in various shapes including square, polygon, and star-shaped with up to 12 vertices. They contain very little mortar and due to the wooded planks and beams that intersperse between the stones, these robust constructions are able to absorb the force of violent shaking that accompany earthquakes. Especially the star-shaped construction that make the structures less susceptible to tremors.

By conducting radiocarbon dating of the wood in the towers, Darragon determined that these towers are between 600 to 1,000 years old. Darragon believes the towers did not serve a single purpose, but its use differed from valley to valley. In Miniak, for example, she believes that many were watchtowers. She bases her conclusions upon such observations like the entrance being several stories above the ground, and the location of the towers where trade routes met. In Kongpo and Damba, the towers seem to be primarily symbols of wealth and pride. According to one tale, the towers were built by locals who grew rich by trading with Mongol-ruled China.

Many of the towers are now in a derelict state. Darragon is working to get the towers listed under UNESCO’s World Heritage Site. The designation would likely help protect the towers and raise money to restore them. She is also trying to enlist Sichuan University’s help in studying the structures. In 2006, the stone towers were placed on the watch list of the World’s Monument Fund, a non-profit organization dedicated to the preservation of historic architecture and cultural heritage sites around the world.