《徐霞客游记·粤西游日记二十》
又向南数丈，有洞弯然隆起横贯东西，洞往上向东张开而成为外洞口，洞内往西进去而形成巨大的壑谷，洞口高耸与前边进来的洞口气势相当。
又南数丈，有洞穹然东西横贯，其上东辟而为外门，其内西入而成巨壑，时二人已至，乃令其以炬更前。
A few more yards to the south, there was a cave, bent and arched, running east and west, the cave opened to the east and became an outer cave mouth, the cave went west and formed a huge valley, the cave mouth was towering and as imposing as the cave mouth I had come in from before.