《徐霞客游记·滇游日记三》
又往西北走一里，忽然看见坞中有坑，坑的正中像井一样坠陷下去，原来这就是坞水流走的地方了。
又西北一里，忽见坞中有坑，中坠如井，盖此水之所入者矣。
Walk northwest for another li, and suddenly see a pit in the valley, and the middle of the pit falls down like a well. This is where the water in the valley flows out.