Study on the subsidiary border wall and its siting layout of the Ming Great Wall

Abstract The border wall system of the Ming Great Wall consists of the main border wall, subsidiary border wall, and various buildings and defense facilities scattered near the main border, forming an in-depth defense system. This paper systematically analyzes the types, spatial layouts, and siting patterns of subsidiary border walls within Ming Ji-Town. Key findings include: (1) the subsidiary border walls can be categorized into three types: parallel, enclosed, and semi-enclosed subsidiary walls; (2) the three types of subsidiary border walls exhibit clustered distribution patterns in terms of defense layout. (3) The spatial distribution of subsidiary border walls shows multi-factor coupling characteristics. The study further discusses the relationship between different types of subsidiary border walls siting and war, and the natural environment. It reveals how natural and military factors interact in military defense construction. It also provides a stronger theoretical foundation for holistic and original protection of the Great Wall heritage.