Introduction to the memorial hall of the former site of the General Headquarters of the Fourth Red Front Army: Tongjiang is the earliest foothold of the Fourth Red Front Army after entering Sichuan. Xu Shuai said: "Lilacaba is the strategic rear area where the Northwest Military Commission agencies, logistics departments and hospitals, The sick and wounded will stay there temporarily. "The anti-six-pronged siege was the most difficult battle we fought in Sichuan."