Photo Provided to China Daily

At the age of 9, Li lived in one of the traditional courtyard homes in a hutong near Houhai Lake. He played football in the alleyways and caught insects with other boys. They ran across the rooftops and fired slingshots at the streetlights.

"I'll never forget the inconvenience of living in the small alley," Li says, laughing. "The public toilets and bathrooms were usually dirty and cold."

However, that was once the true Beijing, Li says. In recent decades, many old buildings, including the city gates, walls and courtyard houses, have been destroyed. Those that survive are scattered among modern buildings, in shrinking islands of the old city.

Those that are protected have lost their inhabitants and are "like lifeless toys", Li says.

The "Open the City Gate" photos have won many awards and built the young photographer's reputation. Magazines commission photos from him; art collectors seek his works; painters are inspired by them.

"Viewers can see in the nine photos the changes that Beijing has experienced - the clash of past and present - and the photographer's deep respect for the old buildings that no longer exist," he says.

Li fears his camera cannot keep up with the changes to the city. "Most greatness has gone with history. We should cherish what survives and create more greatness to compensate for what has been destroyed," he says.