Yuangang Village, formerly an administrative village of Da'anshan Township in Fangshan District, was later placed under the jurisdiction of Da'anshan Coal Mine. The word "gang" in Yuangang is pronounced as "jiang" here. In the Xinhua Dictionary, this pronunciation means "ravine". Perhaps it is because the common people mistakenly think that "gang" means "port", and thus a legend containing the vicissitudes of the entire Da'anshan area has been spread. The old people in Da'anshan said that a long time ago, most of Da'anshan was underwater, and Yuangang above the water was the center of Da'anshan area, and entering Da'anshan area was by water. There is a saying that big ships go to the red coal factory, and small ships go to "tiaotaigen" (sound). Later, the land and water changed, the land rose, and the water of Da'an Mountain poured down, revealing the current Da'an Mountain Village and other places in the low places (now in some places in Da'an Mountain Village, you can still see pebbles in the soil layer of the mountain). The water route to Da'an Mountain was changed to walking on the river beach during the dry season. In this way, Da'an Mountain Village, which was closest to the river beach, replaced the central position of Yuangang Village and became the most prosperous village. The legendary Liu Pen'er, that is, Liu Rengong in history, once built a palace in Yuangang Village for his enjoyment. It is said that when the Beijing Mining Bureau built the Da'an Mountain Coal Mine in Yuangang and built a warehouse on the Anjiafen (near the Da'an Mountain Coal Mine Hospital today), many two-foot square blue square bricks and colored glazed tiles were cleaned out from the slag of the foundation. It is said that this is the historical witness of Liu Rengong's construction of the palace. Legend has it that a flat land near the front desk of Yuangang Village was Liu Pen'er's training ground at that time. Surrounded by barracks, it was responsible for the protection of the palace. This was the last pass. There are four checkpoints to protect Liu Pen'er's Yuangang Village Palace. The first checkpoint is at the "Jiaojunchang", guarded by Liu Pen'er's brother Liu Mengzi; the second checkpoint is the Dameitai and Xiaomeitai guarded by Liu Pen'er's two sisters; the third checkpoint is at the "Tiaotaigen" (sound) on the Dabei River. This article is selected from "Da'an Mountain-Local Customs and People" Information source: District Culture and Tourism Bureau (No pictures, welcome to provide.) Information source: District Culture and Tourism Bureau (No pictures, welcome to provide.)