Zheng He Navigation Chart

In Wu Bei Zhi (A Record of Military Affairs), a book completed by Mao Yuanyi in 1621 (the first year of Tianqi in the Ming Dynasty), there is The Map of Treasure-ship Fleet Sailing to Barbarian Countries from Longjiangguan Pass (aka. Zheng He Navigation Chart). In the map, a host of islands have been named, including Shitang, Wansheng Shitangyu and Shixing Shitang, referring to Xisha Qundao, Nansha Qundao, and the vicinity of Dongsha Qundao and Zhongsha Qundao respectively.

The Map of Treasure-ship Fleet Sailing to Barbarian Countries from Longjiangguan Pass (Block-Printed Edition)