The Erhai Lake, known as Yeyuze or Kunming Lake in ancient times, is named after its ear-like shape. It is a fresh water lake in the Yunnan Plateau at an elevation of 1972 metres.

It starts at Dengchuan in the north and ends at Xiaguan in the south with a length of 42 km and width of 8 km. It is 116 km in circumference and covers an area of 250 square km. The average depth is about 11 metres and the total storage capacity is 2.5billion cubic metres. The Erhai lake is the second largest lake in Yunnan Province, abundant in water resources. The Miju River and the Mici River in the north, the Bolou River in the east and the brooks from the Cangshan Mountain in the west converge into this lake. In the south, the Yangbi River is the outlet and finally converges into the Lancang River.
  
The Erhai Lake is a fault lake formed after a foundering of the earth's crust. The water of the Erhai Lake is limpid. On the lake, there are three islets, four sand banks and eight famous sights. "Erhai Moon" is one of the best sights where one can enjoy the moon mirrored on the lake on a clear night. The Erhai Lake is also rich in aquatic animals.
 
Erhai Park is located at Tuanshan Mountain, 2.5km away from Xianguan. It was once a royal deer ranch of the Nanzhao Kingdom. Built in 1976, the park covers1700 mu of land. Climbing along the path up to the mountain, one can see green pine trees, famous flowers like camellia, magnolia primose, michelia alba and azalea. On the top are the Observation Pavilion and the Long Corridor overlooking the lake, the zoo and the garden. Standing high on the top, one will have a pleasant view of the jade-like Erhai Lake dotted with sails here and there and the silvery Cangshan Mountain. At the shore, there are entertainment facilities such as the aqua park, swimming area, etc. On a clear night, when the moon is mirrored on the lake, one will enjoy one of the most magnificent sights (Wind, Flower, Snow and Moon)-the Erhai Moon in Dali.