Visitors brew tea and rest inside the Wushan Mountain air defense tunnel in Fuzhou, Fujian province, to escape the summer heatwave. [Photo by Chi Yuan/For chinadaily.com.cn]

Residents in Fuzhou, Fujian province, are using a former wartime air-raid shelter to escape summer temperatures that regularly exceed 37 C.

The 570-meter-long civil air defense tunnel in Wushan Mountain, constructed in the 1970s, maintains a constant temperature of 18 C to 20 C due to its deep rock insulation.

Visitors rest inside the Wushan Mountain air defense tunnel in Fuzhou, Fujian province, to escape the summer heatwave. [Photo by Chi Yuan/For chinadaily.com.cn]

The facility was renovated and converted into Fujian's first public cooling shelter in 2013. It links Fuzhou's historic Sanfang Qixiang scenic spot with Liming Lake Park and serves as a free pedestrian passage and community space.

Inside the tunnel, people gather at low-cost stalls to brew jasmine tea, play games, and rest, filling the underground space with a leisure atmosphere.

Visitors rest inside the Wushan Mountain air defense tunnel in Fuzhou, Fujian province, to escape the summer heatwave. [Photo by Chi Yuan/For chinadaily.com.cn]