Introduction to Zhongzheng Gate: The red sandstone arch in the west of the city - Zhongzheng Gate, also known as the West Gate, is the most complete gate preserved among the four sides of the ancient city, and also the most representative one. The Zhongzhengmen is a national cultural relic protection unit. The original city wall was an earthen wall before the Ming Dynasty and was rebuilt in the 14th year of Zhengtong (AD 1450). In the eighth year of Chenghua in the Ming Dynasty (AD 1473), it expanded to the northeast, with a circumference of 5 miles, and all posts were equipped. It was renovated many times during the Kangxi, Yongzheng, Qianlong and Daoguang reigns of the Qing Dynasty. The red-brown boulders in the doorway are uneven due to weathering and erosion, which shows how old it is. In 1938, Dai Li held a special military reunification training class in Qiancheng. When the second class graduated, Chiang Kai-shek came to inspect it in person. At Dai Li's request, he inscribed a plaque with the words "Forsighted and Far-sighted" on the west gate tower. Later, Chiang Kai-shek left Ximen and returned to Chongqing via Zhijiang. In order to seek good luck, Dai Li wrote an inscription and changed the west gate to "Zhongzhengmen".