Takayama Castle, Historic castle ruins in Mihara, Japan.

Takayama Castle is a medieval castle ruin set on Mount Tsumataka above the Nuta River valley, in Mihara, Japan. What remains today are stone walls and dry moats that run along the northern ridge of the mountain.

The fortress was founded in 1206 by Kobayakawa Shigehira as a regional military base. It held a key role during Japan's feudal period before being abandoned as power in the region shifted.

The castle's name combines taka, "high", and yama, "mountain", after Mount Tsumataka, the 150-metre hill it was built on. The site is a National Historic Site, and visitors can still trace the northern ridge's enclosures, defined by stone walls and dry moats, across a layout roughly 600 metres long and 400 metres wide.

The ruins are reached on foot from near the local train station, with a trail through woodland that takes around 20 minutes to climb. Sturdy shoes are a good idea since parts of the path can be uneven.

The fortress once sat at a point that controlled trade routes leading toward the Seto Inland Sea, which made it far more than a simple military outpost. Standing on the ridge today, you can see how wide the field of view was for anyone defending this position.