Dong Mingzhu Building is also called octagonal building because there is a regular octagonal column space running through the whole building.

The following is the floor plan of Dong Mingzhu Building:

North-south longitudinal section

As shown in the two pictures, there are three floors in the center of the building, and each floor is a regular octagonal area, which runs through the whole building together. Due to the ingenious design of the building, few people will notice the existence of this internal area. In fact, this is a regular octagon with a side length of 3.5m and an area of about 60 square meters, which can be said to be a very spacious place.