Hongya Cave, formerly known as Hongya Gate, is one of the ancient city gates in southwest China's Chongqing. Built on stilts to accommodate the slope of the mountain city, its special architectural form makes it look like a scene from a science fiction movie. It is definitely a must-see for tourists visiting Chongqing.

Editor's note: This report focuses on Chongqing as part of our special series "Rising Star Cities," which is about Chinese cities whose annual GDP exceeds 1 trillion yuan ($155.4 billion, or more than the GDP of Qatar). At the end of 2020, there were 23 such cities. Click here for more stories on Chongqing.