Treatise on Armament Technology, Volume 304: Topography — Garrison Defense I

Miyun River Management District Added in the 1st year of the Wanli era [1573].

Twenty-six Coordinating Officers tidiao guan These were administrative military officers responsible for oversight, logistics, and coordinating the defenses of specific sectors or river systems.

Heigu Pass Formerly a Defender shoubei post; in the 40th year of the Jiajing era [1561], it was re-established as Caojia Village; in the 4th year of the Wanli era [1576], the garrison was moved to Heigu Pass [Black Valley Pass].

Jijiazhuang Mouth Pass Added in the 1st year of the Wanli era [1573].

Simatai Established in the 36th year of the Jiajing era [1557] at Gubeikou; in the 40th year of the Wanli era [1612], the garrison was moved to Simatai. Simatai is a famous, precipitous section of the Great Wall. This note tracks the shifting of its administrative center from the major hub of Gubeikou to this specific ridge.

Chao River Stream Pass Established in the 36th year of the Jiajing era [1557].

Kuandiangu Mouth Pass

Yiyuan Mouth Pass

Jieling Mouth Pass