Grottes et karsts de Chine
Sur les traces de Xu Xiake

Hei Dong ‘Diamond Cave’- 25.316407°, 105.595474°

Hei Dong is located in the southern wall of the An He Doline. It has a similar altitude to Xiniu Dong, and appears to be the downstream continuation of that passage before truncation by the formation of the doline. The 50m wide entrance to Hei Dong has a flight of steps leading to the top of a debris pile upon which is sited an abandoned, traditional built house and animal enclosures. Stepping down the other side into the main 40x30m passage the route passes between huge, towering stalagmites before rising up to a narrowing after 150m. Through the obvious gap another flight of steps leads down to a junction. Left leads through several smaller gaps between speleothems into an enlarging passage, which reaches 60m wide before becoming blocked with flowstone.

Right at the junction passes through an array of speleothems before flattening out into more large passage. Gours cover the floor before a wall of flowstone is met. Climbing up the obvious route to the right leads into a chamber with a boulder choke to the left and an impressive line of large stalagmites to the right but there is no way on. Above, at roof level, daylight filters in from another entrance.

Climbing up the flowstone to the left soon arrives at a 12m pitch down. At the bottom there is evidence of nitrate works. Ahead a steep slope continues for 150m, past more huge stalagmites before choking completely. Below the pitch several routes leads down sparkling calcite flows before choking in all directions.

The cave shows evidence of extensive human activity and was certainly visited by the 1988 British expedition although no survey was published. The ease of access, scale and huge speleothems would make this cave suitable for tourist development should there be sufficient demand in the area.