Xiqing Wang/ BBCThe couple stands on the edge of the sheer limestone cliff.
More than 100 metres (328ft) beneath them is a lost world of ancient forests, plants and animals. All they can see is leafy tree tops and hear is the echoes of cicadas and birds bouncing off the cliffs.
For thousands of years, this “heavenly pit” or “tiankeng”, in Mandarin, was unexplored.
People feared demons and ghosts hiding in the mists which swirled up from the depths.
But drones and a few brave souls who lowered themselves into places untouched since dinosaurs roamed the Earth have revealed new treasures – and turned China’s sinkholes into a tourist attraction.
Two-thirds of the…
