City wall in Nanjing city, Jiangsu province [Photo/CGTN]

Living history: ancient city walls

As a cradle of civilization, China’s first city wall was built some 6,000 years ago during the Neolithic Age. As an indispensable part of the ancient Chinese cities, the city walls served as part of the defense systems as well as the architectural experience. It also had political symbolic significance.

In the ancient times, each city's walls were made of different layers varying in scale and form. There were strict rules for the height, width, as well as the number of gates and towers depending on whether the city was the capital, a provincial capital or a county.

The study of these ancient walls have allowed experts to decipher traditional Chinese cultures and history.

“For instance, the city wall of Nanjing. Nanjing’s city walls were not built following the traditional shape of a square. Instead, it was built in accordance with astronomy,” said Yang.

“Originally, the ancient Nanjing city wall had 13 gates, each representing a constellation. The main palace was located at the center of the Plough, and that is why the rulers at that time preferred to fill the lake to build the palaces,” said Yang.

According to Yang, Nanjing’s city wall is a mixture of Taoism which was just taking off at the beginning of the Ming Dynasty (1368-1644) and the special geographic location of the city.