The largest existing ancient city is Nanjing City, which was built when Zhu Yuanzhang, the Ming Emperor, made Nanjing his capital, and it took 2 1 year to complete. In the Ming Dynasty, the circumference of Nanjing was 33.65 kilometers, with an average height of 12 meters and a width of 10 to 18 meters. The city walls are made of stone foundations and huge bricks. City bricks are made of high-quality clay and white porcelain clay, each weighing 20 kg to 40 kg. Bricks are also printed with the names and firing dates of brick makers and brick burners. Glutinous rice pulp mixed with lime is used as adhesive, which is very strong. Despite the stormy weather in June, there are still 20 kilometers of city walls intact. Nanjing has 13 city gates, 65438+3600 battlements and more than 200 fortresses. The biggest is the Jubaomen due south.
There is only 1 Xuanwu Gate in China!