In 1772, the Qing government constructed the second town fortress, some 500 meters to the east of the first one. The 7-meter high town walls form a rectangle of 1,306 meters long and 501 meters wide.

Most of the ancient walls of the towns are still in good condition but the relics of folk houses, government mansions, guild halls cannot be discovered anymore, Jiang said.

Over the past five years, the local cultural heritage authorities have been renovating the relics, reconstructing the gate towers and repainting the walls, in a bid to restore their original looks.

Nowadays, the fortress towns have become a landmark for local cultural tourism. In October 2019, they were listed as a national key cultural relics site.

"The towns are a symbol of the Chinese people's determination to safeguard national unity," Jiang said.