The natural wonders of southwestern China are a sight to behold, and among them are the giant sinkholes known as “tiankeng” or “heavenly holes”. These unique geological formations, formed through the weathering of limestone, can reach depths of over 100 meters and contain lush, ancient forests.
Southwest China’s karst terrain is a result of the erosion of limestone mountains by flowing water. Over time, rainwater seeps through the ground to the bedrock and gradually erodes the limestone. The slightly acidic river water widens the cracks into tunnels and caves, eventually causing the rock ceiling to collapse to the bottom, creating a giant sinkhole.
Zhu Xuewen, a researcher at the Institute of Limestone Geology at the Chinese Academy of Geological Sciences, explains that paradise holes are one of a kind and among the largest sinkholes in the world. The Xiaozhai Tiankeng sinkhole in Fengjie district, Chongqing, is currently known as the deepest sinkhole on Earth. To be classified as a paradise hole, it must be at least 100 meters deep and wide with steep sides and rivers running along the bottom. For example, Xiaozhai Tiankeng features an underground river that flows through the cave during rainy season.
There are around 200 paradise holes in China, primarily distributed from Shaanxi province in central region to Guangxi in southwest. China has more karst terrain than any other country in world. Despite their massive size and remote location within rugged mountains and lush jungle of southwest China, these paradise holes have been discovered only recently due to advances in technology such as drones and satellite imagery.
At their depths lies an ancient forest ecosystem that is home to trees up to 40 meters high with dense foliage reaching shoulder height. This unique ecosystem attracts explorers and researchers from all over world who come to study and marvel at its wonders. It serves as an important reminder of nature’s power
