Izumo-taisha (出雲大社 Izumo Grand Shrine?, also Izumo Ōyashiro) is one of the most ancient and important Shinto shrines in Japan. No record gives the date of establishment. Located in Izumo, Shimane Prefecture, it is home to two major festivals. It is dedicated to the god Ōkuninushi (Ōkuninushi-no-mikoto), famous as the Shinto deity of marriage.
A style of architecture, taisha-zukuri, takes its name from the main hall of Izumo-taisha. That hall, and the attached buildings, were designated National Treasures of Japan in 1952. According to tradition, the hall was previously much taller than presently. The discovery in the year 2000 of the remains of enormous pillars has lent credence to this.
Several other buildings in the shrine compound are on the list of Important Cultural Properties of Japan.

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