This photo taken on July 13, 2023 shows that people embarked on boat ride through Puhua River in Chongqing. /CFP

Visitors to Qianjiang District, Chongqing embarked on a boat ride through a natural tunnel and down a dark river to escape the summer heat amid its cool waters.

The Puhua Dark River stretches approximately 2 kilometers long. With a narrowest point of 5 meters, it is known as the "center of the Earth." Comprised of dark rivers, caves, gorges, and natural bridges over the water, the area maintains a constant temperature of 22°C throughout the year, earning its reputation as a "natural central air conditioner" and becoming a popular destination for people seeking relief from the summer heat.