Plants growing at the bottom of giant sinkholes in China ... a new study finds. The sinkholes, called "tiankeng," are some of the last-remaining natural refuges for ancient forests and may harbor ...

Deep in China's Fengjie County lies a natural wonder that has fascinated experts for decades. The Xiaozhai Tiankeng sinkhole is vast. Probably formed centuries ago by collapsing caves and ...

More than 100 metres (328ft) beneath them is a lost world of ancient forests, plants and animals ... revealed new treasures - and turned China’s sinkholes into a tourist attraction.