Longxi-Hongkou National Nature Reserve belongs to the Chinese geological tectonic system, the middle and southern of Longmen Mountain folding belt, the Yangtze quasi-floor and Qinghai-Tibet trough area in the earth structure, the reverse mask fault is very developed, the cliff is more common, forming the so-called "feilai peak" structure for the lonely mountain on the terrain. The entire reserve is from north to south, with a relative height difference of 3,700 meters, which is a typical alpine canyon landscape. The main peak of Guangguang Mountain is the black granite exposed as a whole, and more than 3,500 meters near the main peak. Quaternary glacier sites such as horn peaks, edge ridges, ice bucket lakes and "U"-shaped valleys are everywhere. These lonely peaks and cliffs are very precious and rare landscapes. Especially the Guangguangshan Ice Dou Lake, which represents the height of the snow line in the ancient glacier era, is calm as a mirror, like a bright giant kitchen knife, and lies quietly in a chair seat. The "chair" is surrounded by mountains on three sides, and the end of the knife handle, that is, the water exit, points to Wenchuan. How warm is the water? How deep is it? Are there fish or other creatures? A series of puzzles to be uncovered by later generations.