At a Glance

The sinkholes are interconnected through an underground river and a cave system.Most of the sinkholes are larger than 35 million cubic feet. Large sinkholes in China are called tiankengs, or "sky holes."

A multinational team of geologists has discovered a cluster of giant sinkholes in southern China.

The found in the Guangxi Zhuang Autonomous Region, which borders Vietnam, according to Chinese news agency Xinhua.

An underground river and a cave system connect the sinkholes, said Zhang Yuanhai, a member of the team that included scientists from China, France and the United Kingdom.

An aerial photo taken on November 16, 2019, shows a newly discovered giant sinkhole in Napo County in south China's Guangxi Zhuang Autonomous Region.

(China's Ministry of Natural Resources via Xinhua)

Most of the sinkholes are larger than 35 million cubic feet, which is bigger than two Yankee Stadiums.

(WATCH: Monster Sinkhole Swallows Truck, Worker in China)

"Some of the sinkholes are formed at a plateau 1,000 meters above sea level, and the others as a chain developed along underground rivers. The founding will be of significance for the theory of sinkholes evolution," said Jiang Zhongcheng, head of the Institute of Karst Geology of China Geological Survey.

Underground caverns form when groundwater erodes limestone. Sometimes the ground over the cavern collapses, and a sinkhole is created.

A member of the team of geologists stands in a cavern inside one of the 19 sinkholes discovered in Napo County in south China's Guangxi Zhuang Autonomous Region.

(China's Ministry of Natural Resources via Xinhua)

In China, sinkholes that are at least 328 feet wide and deep are freelance geologist David Bressan wrote in Forbes.

Bressan said less than a hundred tiankengs are known to exist. They are mainly found in China, Mexico and Papua New Guinea, according to Xinhua.

In October 2018, another team discovered one of the largest sinkholes in the world in the Guangxi Zhuang region.

That sinkhole in the Nongle mountains measured 656 feet long, 328 feet wide and 387 feet deep. Inside, it encompassed 237 million cubic feet.