01 / Oga Castle Site
Stone walls and a gate of huge stoneshave been confirmed at the castle site.

The site is the remains of a mountain castle and castle town built by the Toki clan, military governors of Mino Province, and is a National Historic Site. Excavation at the spot traditionally called the Iwamon gate found a gate formed by a wall of huge stones, up to about 2.5 m wide and 2 m high, a row of standing stones and a stone wall on the slope side. Another excavation suggests a garden with a pond stood in the area traditionally called Daidokoro. Stone walls have been confirmed at about 40 places.
- National Historic Site (designated 17 February 2026)
- Stone walls at about 40 places (2020 survey)
- Castle area about 860 m east-west, 470 m north-south

