《徐霞客游记·滇游日记四十一》
这个山坞南北的两个山坳相距四五十里，非常狭窄而且很深。
焉。是坞南北二坳北都鲁，南哈恩。相距四五十里，甚狭而深。
The two mountain passes in the north and south of this mountain valley are forty to fifty miles apart, and they are very narrow and deep.