This is one of the many 'Oji' shrines along the Kumano Kodo and is located about halfway between Takijiri-oji and the Hongu Taisha (the Hongu Grand Shrine) on the Nakahechi pilgrimage trail.
The shrine itself is not a grand wooden building but simply a large rock with a kanji inscription and a shimenawa, a sacred rope, around it. A small village has grown around the area.
Chikatsuyu Oji is an ideal place for staying overnight on a walk of the trail with inns offering hot springs bath and home cooked meals. You will also be provided with a packed lunch for your next day of hiking if you wish.