A cluster of 54 giant karst sinkholes, also known as "tian keng" in Chinese, have been discovered in northwest China's Shaanxi Province. They are regarded as one of the largest tian keng clusters in the world. Sun Tianyuan explains.

These big holes have finally made their so-called debut, after being discovered and researched for two years. The largest of them is more than 500 meters wide, ranking fifth across the globe. The holes were formed naturally thanks to underground water flows. The water slowly washed away karst rocks and eventually caused the ground to collapse. Hanzhong city in northwest China's Shaanxi Province is believed to be home to one-fourth of all natural sinkholes in the world. And experts say their findings this time can be a game-changer.

HONG ZENGLIN, PRESIDENT SHAANXI INSTITUTE OF GEOLOGICAL SURVEY "Traditionally, sinkholes are more likely to be found in northern China. But now we find well-developed sinkholes in the Qinba mountains. It's a breakthrough."

But getting there is not that fun. Researchers have to navigate dangerous surroundings to reach their destination. However, they soon find out that it's all worth it. Deep inside, the sinkhole is more like a nature museum with dozens of species and plants.

LI RONGSHE, DEPUTY CHIEF ENGINEER XI'AN CENTER OF CHINA GEOLOGICAL SURVEY "We can do deeper research into the ancient climate and rainfall. The sinkholes also give us clues about geological evolution."

An international team of leading scientists and experts will also be assembled for more exploration. Sun Tianyuan, CGTN.