Ichinomiya

is a Japanese term for the chief Shinto shrines in each of the pre-modern provinces.
The "ichinomiya" are the shrines with the highest shrine rank in an area. Shrines of the lower rank are called "ninomiya" (二宮, second), "sannomiya" (三宮, third), "shinomiya" (四宮, fourth), and so forth.
History.
When prefectures were established in the Meiji period, the old system of provincial "ichinomiya" was not changed. Each new prefecture had one or more ichinomiya.