Shintai (Divine Body / Sacred Object)
A physical object in which a kami is believed to reside, housed within the honden
A shintai (literally 'divine body,' also called go-shintai with the honorific prefix) is a physical object believed to house or embody the spirit of a kami. It is the most sacred item at a shrine and is typically kept hidden within the honden, unseen even by most priests.
Shintai can take many forms: a mirror (the most common), a sword, a jewel (magatama), a stone, or a natural object. The three Imperial Regalia — the mirror Yata no Kagami, the sword Kusanagi no Tsurugi, and the jewel Yasakani no Magatama — are perhaps the most famous shintai in Japan.
At some shrines, the shintai is not a portable object but a natural feature. At Omiwa Shrine in Nara, the entire Mt. Miwa serves as the shintai, so there is no honden at all. At Nachi Taisha, the great waterfall is considered the shintai. These cases illustrate the Shinto belief that divinity can reside in nature itself.