The city wall surrounding the third district of Qin Dynasty: the gate, that is, the tower, refers to Chang 'an, the capital of the Tang Dynasty. Assist, escort Sanqin refers to the Guanzhong area near Chang 'an, which is the area west of Tongguan in Shaanxi Province today. At the end of the Qin Dynasty, Xiang Yu broke the Qin Dynasty and was divided into three areas, until Sanqin surrendered, so it was called Sanqin. This sentence is reversed, which means to protect the capital Chang 'an Sanqin. Wujin: It refers to the five major ferries of Minjiang River, namely Baihuajin, Wan Li Tianjin, Jiangshoujin, Shetoujin and Jiangnan Tianjin. This refers to Sichuan in general. Auxiliary Sanqin: one is "overlooking the Western Qin Dynasty".