For the past decade, Cao Yang has been observing and documenting Tianjin in his own unique way. As a real estate agent in Tianjin, he has documented his city through a photographer's lens, capturing its rapid transformation from rooftops and terraces.

His favourite perch is atop an office block in the Heping district, where he watches the city shift from bustle to calm as dusk falls.

"At dusk, looking at the city like this, I feel the hustle and bustle, yet it's also very peaceful," he said.

Cao has turned his passion into a unique project — using satellite maps to track down buildings shaped like every letter from A to Z.

"Taking photos isn't hard; finding them is the challenge!" he laughed.

"Letters are the most basic elements of English, and I hope to use my camera to capture the most basic elements of Tianjin," he said.

Over 10 years, the light and shadows have shifted, and the Tianjin in his lens has changed rapidly, but Cao firmly believes that some things are deeply rooted in the city's essence: "Tianjin is always changing, but its intrinsic humor and spirit won't change."

As lights glitter along the Haihe River, Tianjin prepares to welcome the world to hear its story at the upcoming SCO summit.

Bao Yan contributed to this story.