Sinkholes often spell disaster, but this unexpected limestone cavity is anything but. A botanical delight, this enormous sinkhole was discovered in central China’s mountainous Hubei province. The sinkhole’s remote location—only accessible via a lowered rope ladder—and humid environs has led to its development of a surprisingly lush, self-contained ecosystem largely untouched by man.
The China sinkhole was naturally formed as a result of the region’s karst processes, in which the humid climate of Hubei’s Xuanen county triggered the chemical dissolution of the carbonate landscape. Although the sinkhole was discovered decades ago, only a handful of people have ever plumbed its difficult-to-reach depths. The limestone cavity is estimated to cover a depth of over 290 meters (950 feet) with a ground area of approximately 6.7 hectares (16.47 acres).
Due to its undisturbed location and favorable growing conditions, the sinkhole developed a thriving ecosystem that, until now, was hidden from the public’s eye. Sunlight enters the space through a single craggy opening, while rain and condensation bring water into the hole. The damp and oxygen-rich landscape is lush with abundant plant life—particularly with ferns that thrive in the sinkhole’s humid environment. Fragrant flowers, vines, mosses, palm trees, and more have also sprung up to create the thick green carpet that lines the sinkhole floor. Hundreds of swallows have nested along the sinkhole’s cliff faces and feed on the flourishing butterfly and insect populations.
Images via Xinhua