The imposing city wall, as high as a five-storeyed building, very impressive to the visitors to Nanjing. The Building of the wall began in 1366, ordered by Zhu Yuanzhang who adopted the suggestion of "building the high wall" by one of his staff and founded the Ming Dynasty two years later. More than 200000 people were employed on the project and man of them died before the wall was completed in 1386.

The first entrance is in a three-tier building in which 27 tunnels are built.These tunnels are spacious enough to quarter more than 3000 soldiers and store large quantities of food and ammunitions. There are wide horse ramps on both sides. At the top, there used to be a rostrum allowing a commanding view. Unfortunately, the rostum together with other parts of the wall was destroyed by the Japanese invaders in the Anti-Japanese War.