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.

Wakayama Prefecture is a prefecture of Japan located in the Kansai region of Honshu. Wakayama Prefecture has a population of 944,320 and has a geographic area of 4,724 square kilometres (1,824 sq mi). Wakayama Prefecture borders Osaka Prefecture to the north, and Mie Prefecture and Nara Prefecture to the northeast.