Yihai Lake is located at Yangping Mountain in 40 km north to Mianning county capital, with an area of 1 km2 and a planned protection area of 30 km2, and it has a special roads in 7 km length connecting to No.108 national highway.
On May 22, 1935, the commander Liu Bocheng and the commissar Nie Rongzhen of the advance unit of Chinese Workers and Peasants’ Red army reached Yihai Lake and swore to be allied brothers with Xiaoyueda (Xiaoyedan)—the head of Yi Nationality, enabling the army to pass the Yi area. Now, the place where the ceremony of alliance was held has become a protected cultural unit and a tourist resort of Sichuan Province.
Yihai Lake belongs to a freshwater lake in mountainous region, with fresh air, and watched from high place, the lake is like a shining sapphire in mountains, radiant and keen. Around the lake, there are dense distribution of ancient trees and grasses, as well as azalea, camellia and lilac. The wild ducks in groups are paddling in the water. Walking along the lake, you will feel like in a wash drawing, pondering and pleasant.