Introduction to Yaofang Cave: Yaofang Cave is named after many Tang Dynasty medicine prescriptions engraved on the cave door. There are more than 150 kinds of medicinal prescriptions engraved on both sides of the cave door, and the medicines used are mostly plant, animal and mineral medicines. The prescriptions in Yaofang Cave are the earliest existing stone-engraved prescriptions in China, and they play an important role in the study of Chinese medicine.