2. "And one person guards it, and ten thousand people can't force it" is the source of Li Bai's Shu Dao Nan in the Tang Dynasty: the mountain is high and dangerous, and one person guards the pass, and tens of thousands of people can't get in, which describes the terrain as very steep and has strategic significance.
3. About Jianmenguan, Zhuge Liang repaired Shu Dao during the Three Kingdoms period. He saw the steep terrain here and there was a natural pass between the two mountain valleys, so he built a checkpoint as a barrier between Shu and Han.
4. After Zhuge Liang's death, Jiang Wei led the army to resist Wei Jun of Zhong Hui, until Shu Han surrendered to Wei.