The Himalayan Towers of China

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