"Both the Forbidden City in Beijing and the Great Wall were included on the UNESCO World Heritage List in 1987, and if the Forbidden City is a spot on the map, then the Great Wall is a line, which guards traditional Chinese culture," Shan says.

Unlike the Palace Museum, the Great Wall is located outside of any city or center of population.

"So, to tell the stories of the Great Wall has become an important way to 'make the Great Wall active' and bridge the gap between it and the public," Shan says.

In April, the China Book Review announced the top books about China of 2019 and an illustrated handbook, Visualizing the Great Wall, was one of the winners.

Shan considers Visualizing the Great Wall as a micro encyclopedia of the iconic monument with graphics and texts.