Photo Provided to China Daily

The city planners only left "one and a half" city gates. The one gate is Zhengyangmen, on the south-north axis of Beijing at the south end of Tian'anmen Square. Built in 1419, it is also called Qianmen, or "Front Gate". Bereft of its side walls and barbicans, Qianmen has been restored with a new face. The "half" is the Deshengmen archers' tower, near Li's former home.

But inner Beijing is still encircled with the names of the old fortifications, including the dismantled ones like Chaoyangmen and Xizhimen.

Li named the nine photos after the 2001 article, "Open the City Gate", by Chinese poet Beidao, who returned to Beijing after many years abroad and found that his hometown was unfamiliar after its dramatic changes. He decided to "rebuild" the old city in words, recording the smells, sounds and images that used to exist.

Almost a decade later, fellow Beijing native Li chose to "rebuild" the city in his darkroom. "My camera has been shuttling from the old solemn city gates to the glitzy new buildings along the roads, and I am experiencing the different speeds of two eras. The city is now fast and furious, far removed from the time of simplicity and tranquility, in which the city gates were built," he wrote in a newspaper article when his photos were published in 2012.

Today, his works are widely shared and appreciated online.

"They are excellent records of the old city and a sorrowful reminder for its residents," reads an entry posted on the Chinese micro blog Sina Weibo.

Some scholars have pointed out that the images are not accurately aligned to the original locations and orientations of the gates. But Li says, "I just want to jog people's memories with the strong conflict of images."