The Beijing sections of the Great Wall are one of the most well-preserved and complex among those meandering through more than 10 provinces, autonomous regions and municipalities. They run more than 520 kilometers across six districts in the city.

In 2021, Beijing shifted its focus from general protection of the Great Wall to research-based restoration, selecting the Dazhuangke section in Yanqing and the Jiankou section in Huairou as pilot sites for research-based restoration.

"Previously, we only observed the Great Wall from the surface and didn't understand the buried parts, making it difficult to create comprehensive and scientific protection plans. By using archaeological methods to observe, diagnose and treat, we can identify the root cause of the Great Wall's issues and provide targeted treatments," Shang explains.

In recent years, artifacts unearthed from the Great Wall in Beijing can be categorized into three major types: architectural components of the wall, weapons and daily utensils, Shang says.

In 2022, researchers discovered charred grains from the Ming Dynasty (1368-1644) on the Dazhuangke section of the Great Wall, including millet and Chinese prickly ash.

Although these grains were charred, they have provided an authentic representation of the daily diet of the Great Wall garrison soldiers, Shang says. He notes that a pile of more than 50 stone grenades found on the Badaling Great Wall last year was a major discovery.

"This updates our previous understanding of the weapons used by the Great Wall garrisons. We used to think that they mostly used long-range weapons and that there weren't many close-combat weapons," Shang says.