The largest and deepest sinkhole in the world is Xiaozhai Tiankeng, in Fengjie, China. Its name means something like "well of heaven".

With its 662 meters deep, 626 meters long and 537 meters wide, it is one of the most impressive natural attractions on Earth. In addition to a great variety of fauna and flora, it is home to an underground river that measures a total of 8.5 km that ends in a spectacular waterfall. In the rainy season, a waterfall is also generated at the mouth of the sinkhole.