Big Enough to Swallow Cities and Hide Skyscrapers — A ‘Lost World’ Lies Within

In the mountains of Chongqing, China, Xiaozhai Tiankeng opens into a limestone void so deep that many famous skyscrapers could stand inside it. Its sheer scale has encouraged city-swallowing comparisons, although those descriptions are dramatic metaphors rather than literal measurements.

Far below the rim, forest, water and wildlife occupy a cooler, wetter environment partly separated from the surrounding landscape. The “lost world” is a genuine ecosystem, but it is neither completely sealed off nor untouched by people.