Cao Cao Underground Military Tunnel Scenic Area, a 4A-level attraction and the No. 1 must-see in Bozhou (Figure 1), is a national key cultural relics protection unit and the oldest and best-preserved large-scale underground military facility in China, known as the "Underground Great Wall" (Figure 2).
The scenic area is divided into two parts: the "Jian'an Literature Museum" and the "Underground Military Tunnel."
The Literature Museum, located in the Qiaowang Tower (Figure 3), is the only museum in China dedicated to systematically showcasing Jian'an literature (Figure 4). The museum focuses on the Three Caos (Cao Cao, Cao Pi, and Cao Zhi), the Seven Scholars of Jian'an, and Cai Wenji, highlighting the generous, poignant, and robust style of Jian'an literature (Figure 5), which complements the military content of the Three Kingdoms period in the military tunnel (Figure 6).
The Underground Military Tunnel, the core of the scenic area, is nearly 8,000 meters long, with approximately 700-800 meters currently open to the public (Figure 7). The tunnels retain ancient military installations such as cat-ear bunkers, obstacle courses, tripping boards, and traps, and have two levels (Figure 8), forming a complex, maze-like structure. The tunnels are 1.5-1.7 meters high and only 50 centimeters wide; in some low and narrow sections, one can only pass by crouching and turning sideways (Figure 9).
Being there immediately evokes the magical tunnels depicted in the film *Tunnel Warfare*, and further reinforces the profound wisdom and exceptional skill of the ancient military strategists.