Introduction to the rock coffin: On the cliffs of Longchangdong Gorge, there is a funeral ceremony for the ancient Ba people, ancestors of the Tujia people. It was formed at the end of the Spring and Autumn Period and the Warring States Period and has a history of more than 4,000 years. According to expert research, there are seven rock coffins here, two of which are exposed and clearly visible. It is still a mystery on Shennong River.