Introduction to Bonan Mountain: Bonan Mountain and Luomin Mountain are seen in the distance. The mountains are steep, shaded by trees, and smoke is blurred. At the western foot of the mountain, there is the rolling Lancang River as a natural barrier, thus forming the military commanding heights "Dingdang" on the top of the mountain. Pass" and became a military outpost in the history of our country. Therefore, Bonan Mountain has also become the most important threshold on the entire ancient road, and the ancient road that runs through the entire mountain has become the most dangerous and famous section of the entire "Sichuan Poison Road".