The Shandan Great Wall was created by building a tight defense system of pavilions, trenches, beacon towers and setting up passes, and it became a crucial component of the defense system in the Hexi Corridor. In 111 BC, Shandan county was founded as an important customs fortress along the Silk Road.

During the Ming Dynasty, it was also a crucial part of the defense system of the Ming Great Wall. According to Xu Huijun, researcher at the China Academy of Cultural Heritage, the constant reinforcement and improvement to castles, beacon towers and bastions since 1537 created the best-preserved Great Wall made of rammed earth visible in Shandan today.

The Shandan Great Wall is known for its variety of architecture and complete defense system, including walls, fortresses, moats and beacon towers. Construction materials are diverse, primarily rammed earth, adobe, and brick and stone masonry, with some structures employing a mix of earth and stone, or incorporating reeds.

"The construction methods fully embody the principle of adapting to local conditions and using local materials," Xu says.

The Shandan Great Wall not only embodies the overall architectural characteristics of the Great Wall but also displays distinct local features, and so is representative of the earthen defensive walls of Gansu and the rest of the country, she adds.

Spanning loess gullies, mountains, and deserts, the Shandan Great Wall provides valuable physical evidence for studying the history, geography, politics, economy, military affairs and culture of the northwestern region, she says.