Introduction to the Fifth Army Tunnel: The Fifth Army Tunnel is located in the Yuejiang Tower Scenic Area, above the ancient fort. The tunnel is 2 kilometers long and covers an area of 20,000 square meters. Over the past century, it has been built by the Qing Army, the Taiping Rebellion Army, the Japanese Army, the Kuomintang Army and the People's Liberation Army, so it is called the "Five Army Tunnel".