Rugged peaks shrouded by mists and fogs, they were the mysterious, terrifying abodes of supernatural beings. During the Tsin dynasty (265-420 A.D.) Ke Hung wrote a treatise on the best methods to enter these sacred mountains. These principles later became incorporated into the general tenets of Taoist philosophy.
到了東晉葛洪所著「抱朴子」一書中，他不但提到山中種種怪物，還提供了許多入山的方法，練功入山遂成道教修行的重要部分，而「三年尋龍，十年點穴」則是入山的主要目的之一。