About Mount Kōya

Mount Kōya is a large temple settlement in Wakayama Prefecture, Japan to the south of Osaka. In the strictest sense, Mount Kōya is the mountain name (sangō) of Kongōbu-ji Temple, the ecclesiastical headquarters of the Kōyasan sect of Shingon Buddhism.
Garbhadhatu (Sanskrit) or Taizo-kai (jp.) - Mandala

Shingon Buddhism – The Japanese root of Esoteric Buddhism

Shingon Buddhism is one of the major schools of Buddhism in Japan and one of the few surviving Vajrayana lineages in East Asia, originally spread from India to China through traveling monks such as and . Known in Chinese as the Tangmi these esoteric teachings would later flourish in Japan under the auspices of a Buddhist monk named (空海), who traveled to Tang China to acquire and request transmission of the esoteric teachings. .