Iwakiyama Shrine (岩木山神社 Iwakiyama jinja) is a Shintō shrine in the city of Hirosaki in Aomori Prefecture, Japan. It is the ichinomiya of former Tsugaru Domain. All of Mount Iwaki is considered to be a portion of the shrine. The main festival of the shrine, the Oyama-sankei, features a parade from the shrine to the top of the mountain, and is held annually at the time of the autumn equinox. The pilgrims carry colorful banners and are accompanied by traditional drums and flutes. …https://en.m.wikipedia.org/wiki/Iwakiyama_Jinja
The foundation of the Iwakiyama Shrine predates the historical period, and Mount Iwaki was a holy mountain for the local Emishi tribes. Per shrine tradition, the shrine was established on the summit of Mount Iwaki in the year 780. It was rebuilt by the folk-hero Sakanoue no Tamuramaro in the year 800 and dedicated to his father Sakanoue no Karitamaro. Several subsidiary shrines were built around the base of the mountain in an area called the Tokoshinai (十腰内) by the local inhabitants. One of these subsidiary shrines to the southeast of the mountain developed into the Shingon sect Buddhist temple of Hyakutaku-ji (百沢寺) in 1091, and became the predecessor of the present shrine. The three main peaks on Mount Iwaki were identified with the Buddhist deities of Amida Nyorai, Yakushi Nyorai and Kannon Bosatsu. During the Meiji period’s government-ordered separation of Buddhism from Shinto, the temple became a Shinto shrine. In 1871, it was officially designated one of the Kokuhei Shōsha (国幣小社), or 3rd ranked national shrine under the State Shinto system until 1946. ..https://en.m.wikipedia.org/wiki/Iwakiyama_Jinja