《徐霞客游记·黔游日记六》
这个洞口向西径直穿过山腹而出，约有七丈多长，前后两个洞口相通，互相望得见，可从下面看不见的原因，是因为洞在高处。
其门西径山腹而出，约七丈余，前后通望而下不见者，以其高也。
This cave entrance went straight through the mountainside to the west, it was about seven feet long, the two entrances were connected, and you could see each other, but you could not see it from below, because the cave was high.