Hayashi Castle Ruins

Nagano, Japan

---

Hayashi Castle Ruins in Nagano, Japan, were constructed in the mid-15th century by Ogasawara Kiyomune as a mountain fortress to protect the Ogasawara clan's territory in Shinano Province. The castle complex actually consisted of two parts: a larger residence castle (Ōjō) and a smaller, more defensible fort (Kojō) on adjoining hills.

Its design included clay walls, stone terraces, and dry moats, with structures built to suit the mountainous terrain. Despite its strong location and defenses, Hayashi Castle fell to the warlord Takeda Shingen in 1548, marking a key moment in the region’s Sengoku period conflicts.

Though largely in ruins today, remnants such as stone walls remain visible, reflecting its importance as a historic stronghold and residence of the Ogasawara clan before they shifted to Matsumoto Castle.