Datong city wall is one of the most well-preserved city walls in China. It's bigger and taller than the ones in Pingyao and Xi'an. Though it was rebuilt, that process was based on a very accurate blueprint from nearly a century ago. [Photo by Zhang Xingjian/chinadaily.com.cn]

Datong city wall is one of the most well-preserved city walls in China. It's bigger and taller than the ones in Pingyao and Xi'an. Though it was rebuilt, that process was based on a very accurate blueprint from nearly a century ago. [Photo by Zhang Xingjian/chinadaily.com.cn]