Introduction to Tengjiao Chiyan Mountain: Chiyan Mountain is commonly known as Yinkeng Mountain. It is located in Tengjiao District, with Longqiu on it, and the mountain produces silver mines. It was mined in the 11th year of Yongle (1413) and later banned. There are still remains of the silver mine today. It is said that landscape poet Xie Lingyun visited here when he was the prefect of Yongjia.