What is the relationship between Zhong Nanshan and Hanguguan?

Zhong Nanshan is quite famous in history. It is the birthplace of Buddhism, Taoism, the god of wealth and the birthday boy. Laozi, the ancestor of Taoism, had an apprentice named Yin, who was originally a customs official in Hangu. Dissatisfied with the decrees of the Eastern Zhou Dynasty, he decided to live in seclusion in Zhong Nanshan. One day, I went to Zhongnanshan to watch the stars, and found that the astrology had changed, thinking that there would be a saint visiting. Sure enough, after a while, I was greeted by Lao Tzu Yin.