《徐霞客游记·江右游日记四》
我从岩洞边一直奔向南面，路断绝的地方崖壁被凿开，到了岩的边缘处，崖壁高峻陡直，不可往下俯瞰，忽然有个洞贯通山峡显露出来。
从岩畔直趋而南，路断处辄为开凿，既竭走完岩端，忽有洞透峡而出。
I ran south from the rock cave, and when the road ended, the cliff had been cut through. When I reached the edge of the cliff, it was high and sheer, and I couldn't look down. Suddenly a hole appeared, connecting to the canyon.