Hidden within the Dajiahan Tribe's "Birhikan" is a secluded treasure of Wanyuan Township. Originally a piece of farmland, this pool was transformed into a dam by the Dajiahan Tribal leader Birhikan, who dug and donated the land. However, over time the dam deteriorated and collapsed. Birhikan's eldest son later repaired it, channeled mountain spring water into the pond, and named the pool "Birhikan."