The image is a photograph of a sign on a concrete wall that reads "Tunnel Warfare". The sign is rectangular in shape and has a black background with white text. The text is written in both English and Japanese.

The text on the sign explains that tunnel warfare is a tactical way, which depends on tunnels to fight against the enemy. It is an efficient way invented by the Chinese army and local people in guerrilla war in order to deal with the brutal mopping-up campaign launched by the Japanese troops and persist in fighting against the Japanese in the vast plain area, the army and the people adjust measures to local conditions, which connects every house and every village and in which the people can hide and fight. Depending on the tunnel net, every village can fight independently. Being able to attack and defend efficiently in tunnels, people can assault the enemy when they are off guard in and out of villages, on and under the ground. Tunnel warfare plays a very important role in the Anti-Japanese guerilla war in the plain area.