"Emerging from the mountains, the white stones shine as bright as jade." This sentence is describing Bishan, a district located in western Chongqing. With its picturesque scenery and pleasant climate, it has been attracting more and more people to come here, including Mr. Zhuang Nu, who is acclaimed as one of the "Three Talented Wordsmiths". What is the reason behind his deep affection for Bishan?