Today, tong lau remain hives of social and commercial activity, home to densely-packed communities and small businesses like restaurants and pawn shops.
Wah Fu Estate in Hong Kong. "They have these quite distinctive features that are unique to this area, and southern China in general. I see (this photography project) as documenting the situation, and a kind of celebration of heritage," photographer Stefan Irvine told CNN.
Tong lau buildings are often located in densely populated parts of the city, posing a challenging for Irvine, whose digital stitching method requires multiple photographs to be taken from the same height and perspective.
"It's key for me to be able to find enough space opposite a building so I can walk along in a straight line with my tripod taking shots that I need," said Irvine, who moved to Hong Kong in 2002. "It's actually much harder to find than you might think.
