'Mountain shintai'. Also called kami-yama. A number of sacred mountains function as shintai and their shrines therefore lack a honden. An example is Mt. Miwa, the shintaizan of Omiwa Jinja, where the mountain is an example of a kinsoku-chi or 'confined place' which forms part of the shrine. In other cases where the mountain is recognised as the kami of a shrine, a man-made shintai in the shrine may act as a substitute for the mountain. The idea of the mountain as kami may be connected with ta-no-kami and yama-no-kami beliefs.
A Popular Dictionary of Shinto. Brian Bocking.