Bell and Drum Towers, December 2007. The snow-capped roofs dominate the photo in stark black and white. No one is in sight.[Photo by Bai Hao/For chinadaily.com.cn]

"I don't remember how many photos I've taken－maybe hundreds of thousands," says Bai. "As someone living in Beijing, I'd better do something to save the city's memories."

Life in the hutong and siheyuan (quadrangle courtyard houses) is a major theme of his photography, which he says reflects the city's "urban ecology".

His systematic recording of Beijing's traditional neighborhoods started in 1998, when massive urban construction began to dramatically change the lives of people living in traditional houses.

At the beginning of his project, Bai intended to take photos of tombs of former nobles of the Qing Dynasty (1644-1911) rather than the hutong areas.