Introduction to the former site of the headquarters building: The headquarters building is part of the former site of Unit 731. It was built in 1938 and is a brick-concrete structure with a height of two stories. The building houses the former captain's office of Unit 731, the guard's office, a diagnosis and treatment room, a specimen display room, a military police room, etc. It is the base camp for developing bacterial weapons and directing bacterial warfare. The headquarters building is connected to the bungalow on the south side through a central corridor that is 50 meters long and 4 meters wide. One building is the equipment supply department, and the other is the weapons depot. It was later restored to maintain its current appearance.