Shanjuan Cave. [Photo/WeChat account: wuxishilvyouju]

As Wuxi swelters under a string of extreme heat warnings, residents are discovering an unlikely antidote to the summer blaze — not by the water, but deep underground.

While many have flocked to mountain streams and forest shade to cool off, the city's network of limestone caves offers a far more dramatic drop in temperature, with some maintaining a steady 15 degrees Celsius year-round.

Shanjuan Cave in Yixing stands out as a geological wonder where stalactites form a spectacular underground landscape. The cave's subterranean river allows visitors to drift by boat, with cool mist rising from the water and temperatures hovering around a comfortable 20 degrees Celsius.

Rides through Muli Cave offer stunningly illuminated views. [Photo/WeChat account: wuxishilvyouju]

For those seeking a more chilled-out vibe, Huoran Cave at Plum Garden maintains a steady temperature of 28 degrees Celsius — a stark contrast to the nearly 40 degrees Celsius outdoor conditions.

The cooler options lie farther afield. Linggu Cave in Yixing, known for its layered sedimentary rock formations that preserve billion-year-old marine memories, keeps a constant 16 degrees Celsius. Muli Cave in Yixing maintains a similar 16 degrees Celsius. Visitors can explore its underground waterways either on foot or via a water train.