《徐霞客游记·浙游日记下》
岭西面又形成一个山坞，从山坞北面进去，仍折往东走，这时离开双龙洞约有五里远了。
岭西复成一坞，由坞北入，仍转而东，去双龙约五里矣。
A mountain col is formed again on the west side of the ridge. From the north side of the col, we still turn to the east. At this time, we are about five miles away from the Shuanglong Cave.