https://nypost.com/2022/05/18/630-foot-sinkhole-in-china-reveals-massive-ancient-forest-world/ Chinese cave explorers were stunned after discovering a huge sinkhole about 630 ft deep, which contained a forest at the bottom, "and possibly other animals, like a lost world." The pit is one of 30 known to the authorities, located in Li Province, in the Guangxi Zhuang Autonomous Region of southern China.