Since the Nara period, high or beautiful mountains in Japan have been the object of a mountain religion, so some people began to implement their ascetic deeds on mountains; subsequently, these deeds developed into shugendo (Japanese mountain asceticism and shamanism incorporating Shinto and Buddhist concepts).
奈良時代より、高い山や、美しい山は霊山として山岳信仰の対象とされ、山地に於いて修行する者も現れ、それらは後に修験道へと発展していった。