A map of the Hengshui and nearby valleys in Hebei, the 1st "Inner 3 Passes Map" (<i>Neisanguan Biantu</i>) from Luo Hongxian's <i>Enlarged Atlas</i>, Vol. 2, based on the maps first drafted by Zhu Siben. Library of Congress copy of Hu Song's 1558 revision. The 3 Inner Passes were the Juyong, Daoma, and Zijing Passes, three important gates in the Great Wall on the routes west from Beijing. The Great Wall itself is not depicted. Each square 100×100 li (about 33×33 km or 20×20 mi).
Zhu Siben, redrafted and revised by Luo Hongxian
1558
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