Ningwu County Zhaizhen located about 1 km northwest, according to "Shan Hai Jing" says: "Guancen of the mountain, Fenshui the Yan", so future generations that this is the Fen River water source.
At the source is a reservoir, pond on the four characters carved stone walls, "the source Ling Fen marsh", a carved stone walls in the lead, in a puff of Longkou springs, flowing all the year round without a break. There is a temple near the source, called thunder Temple, built in the Ming Dynasty, after the destruction.