Introduction to the ancient castle around the mountain: When you climb to the top of Baishi Mountain, you can see a white city wall surrounding the mountain. There are city gates every one or two hundred meters that communicate with the outside. There are watch towers on the city gates. Legend has it that this ancient city wall surrounding the mountain was built during the Xianfeng period of the Qing Dynasty, which was the middle period of the Taiping Heavenly Kingdom. This city wall is winding and winding, with a "little Great Wall" like a jade belt, which has become one of the wonders of Baishi Mountain.