Located in a remote valley, temple 12, Jyufukuji, has no firm date for its founding, though it was a Jinguji so that suggests the Heian Period.
Jinguji were temples built next to shrines, and Jyufukuji was built to administer to Iiwa Shrine, which I have not yet been to but intend to. Iiwa Shrine is listed in the Izumo Fudoki, so dates back to ancient times and is unusual in that it has no honden, rather behind the shrine is a large rock which functions as the honden.
Originally a Tendai temple, in 1570 the local daimyo, of the Mori clan, converted it to Soto Zen
It is now some distance from the Iiwa shrine, so I suspect it was moved to its present location in early Meiji when most jinguji were destroyed or moved.