Introduction to Yingen Gate: During the Ming Dynasty, three cities, namely the Old City, Pianyue City and New City, were built in the ancient town of Zhongshan, known as the "Three Cities". During the "Great Leap Forward" and "Cultural Revolution", Zhongshan City was destroyed, and now only one Ying'en Gate remains, telling the world about the glory of the ancient town and the vicissitudes of history.