In the Thunder God Cave, there is a stone hall imitating a wooden structure, which is exquisitely made. This stone hall was originally built in the Yuan Dynasty and was renovated in the Ming Dynasty. The components above the dougong brackets are retained from the Yuan Dynasty, while those below the lintel are made of bluestone from the Ming Dynasty. It reflects the architectural techniques and craftsmanship of the Yuan and Ming dynasties. Behind the stone hall, there is a natural pool that never dries up all year round and is called the Spirit Pool. The Thunder God Cave is the only place on Wudang Mountain where the Thunder God is enshrined alone, and it holds significant importance in the study of Wudang Taoism. The thunder god is a mysterious creature in ancient mythology, that is, a kui with only one foot. This monster looks like an ox, with a blue body and no horns. It has only one foot. When it comes out of water, it will surely encounter wind and rain. Its light is like the sun and the moon, and its sound is like thunder. ... The Yellow Emperor obtained it and used its skin as a drum and the bones of the thunder beast as a peg. Its reputation spread for five hundred miles, and it was feared throughout the land. The record here that "it must come out of wind and rain, its light is as bright as the sun, and its sound is like thunder" might be the natural phenomenon of thunder and lightning. Thus, the natural one-legged kui became the earliest form of the rumination of the thunder god.