People does urban exploration and walks Anyang art park near Seoul. [Photo by Zhang Yu/provided to China Daily]

"We do it for photography, to find fresh angles to present a city," he says. "Once you give it a shot, you get addicted to it."

Thanks to social media, this new generation of urban explorers is able to expand this subculture.

They use smartphones and digital cameras to capture their excursions, and then upload them on social media sites such as WeChat, Visco and Instagram.

As a Beijinger, Zhang has seen traditional scenic spots such as the Summer Palace, the Forbidden City and the Temple of Heaven since childhood.

"When you are familiar with certain spots, you get bored," he says. "I want to discover hidden gems so that others can see a Beijing that defies general impressions."