Butterfly Spring is located at the foot of the Yunnong Peak of Cangshan Mountain to the north of Dali. A local legend tells the tale of how it was named long ago. A beautiful Bai maiden named Wengu was spotted by a local despot who wanted to take her as his concubine. The girl refused and she and her lover drowned themselves together in the pool and emerged from the pool as a pair of butterflies. It is also claimed that the lovers return as butterflies every spring.