Subsequently mountain worship in Ancient Shintoism was fused with Esoteric Buddhism, Zen Buddhism, and Taoism (Onmyodo, or Way of Yin and Yang, which is an occult divination system based on the Taoist theory of the five elements), and tohai (mountaineering for worship) under Shugendo (Japanese mountain asceticism-shamanism incorporating Shinto and Buddhist concepts) became active.
後世には古神道における山岳信仰が、密教や禅宗や道教（陰陽道）と習合し、修験道における登拝も活発化した。