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 many of them died before the wall was completed in 1386.
the wall was 33.678 kilometers in circumference and 14.21 meters high on average. the base of the wall is 14meters wide and the top of the wall is 7meters wide. it was the longest city wall in the world and the city enclosed by it remained the world’s largest until the 17th century. great part of the wall base is made of granite or rectangular slabs of lime stone, and both sides of the wall are laid with huge bricks. each brick is 45 centimeters long, 20 centimeters wide and 10 centimeters thick with a weight of 15 kilograms. the bricks were cemented in with a mortar of lime mixed with tung oil and glutinous rice gruel. in order to guarantee the quality of the wall, zhu yuanzhang had tight control over the making of all bricks. the brick-makers and the officials were responsible for overseeing the quality. in case a brick was found not up to the standard, all of them were supposed to be punished. therefore many parts of the wall are still in good condition.
different from the square-shaped city walls of most ancient chinese cities , the wall of nanjing followed the natural topography and formed an irregular shape. by this construction, natural barriers, such as mountains, rivers, and lake were all employed to strengthen the fortification of the city. the city wall has 24 gates, among which only 13gates were the original ones from ming time and the rest were built or added for traffic purpose later on.
among all the gates, zhonghua gate is the largest. the gate was formerly called the treasure bowl gate, which is connected with an interesting story popular among the local people. in the early ming dynasty when emperor zhu yuanzhang stared to build a city wall around nanjing , everything was well done, except that this gate failed to be built after many attempts. from his prime minister, the emperor heard of a poor fisherman named shen wanshan, who got a treasure bowl and became very rich. the imperial court dispatched people to cheat him out of the reassure bowl and buried it into the ground as the foundation of the gate. the gate was finally built up. from the time the gate was given the name jubao in chinese which means treasure bowl .
covering an area of 15168 square meters, 20 meters high, the gate has 4 entrances with 4 doors. behind the first conventional double panel wooden door, there are 3 other 23-centimeter-thick vertically sliding stone doors. the heavy stone doors are lifted and dropped with the help of a mechanical winch. if enemy troops broke through the first wooden door, they could be separated and trapped inside by the dropping of the other 3 stone doors. this strategy is known in china as “beating dogs behind bolted door.”
the fist 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 rostrum together with other parts of the wall was destroyed by the japanese invaders in the anti-japanese war.
nowadays, 21.35-kilometer city wall survives and is among the preservation list of monuments and historical sites approved by the state council . the nanjing municipal government plans to have part of the city wall repaired and some of the city gates renovated.