Introduction to the chessboard stone: 60 meters southeast of the main road of Shuangshan Big Turn, there is a smooth boulder about 5 meters long and 3 meters wide. The horizontal and vertical stone patterns on it are densely packed like a chessboard. It is said that there is a person with the surname Zhang in the Dengjiazhuang behind the mountain who is usually charitable and devoted to Taoism. That day he went to the mountains to collect firewood. When he reached Shuangshan Pass, he saw two old men playing chess on the roadside stones. Each of them made a pot of tea. He went over and watched for a while and said to an old man: "You made a wrong move." The old man glanced at him sideways and said: "Do you know how to play chess? Are you thirsty? Please drink some tea." Zhang's surname After walking for a long time, my mouth was indeed a bit dry, so I took a few sips of tea. After drinking it, I felt like my eyes were glowing with gold, I felt dizzy, and I fell asleep involuntarily. When I woke up, the two old men were gone. When the family inquired about it, they found that even his children had been dead for many years. It turns out that what he drank was the immortal tea inspired by the immortal, and he has become an immortal. What is left now is the chessboard stone where the two immortals played chess.