Introduction to Tianyin Cave: Tianyin Cave is located under Youlong Valley. It starts from Bilianchi and goes straight up to the top of Longtou Peak, which is more than a thousand meters long. Inside the cave, there is gurgling water, rugged stone formations, and a hole in the cave that goes vertically down and is unfathomably deep. There are several "skylights" on the top of the cave, and a ray of sunlight shines through the gaps in the rocks, which is even more fascinating. When you are in the cave, you will feel the breeze blowing all year round, which is refreshing and pleasant.