Komaru Castle, Castle ruin and archaeological site in Echizen, Fukui Prefecture, Japan

Komaru Castle is an archaeological site in Echizen featuring stone ramparts, dry moats, and foundation traces positioned on a small hill. The remains show the layout of a fortified military structure with defensive features and building foundations from the 1500s.

Sassa Narimasa, one of Oda Nobunaga's generals, began building Komaru Castle in 1575 after being tasked with suppressing the Ikkō-ikki in Echizen Province. In 1581 he was transferred to Etchū Province, and the unfinished castle was abandoned after only six years. Records confirm Sassa as the only known lord of Komaru; Maeda Toshiie resided at nearby Echizen-Fuchū Castle.

Roof tiles unearthed in 1932 carry an inscription on their reverse describing Maeda Toshiie's suppression of the Ikkō-ikki in Echizen through mass executions of followers. The tiles were found during excavations that also revealed the honmaru gate and dry moat.

The ruins lie on a hill on the Ajimano fan built by the Kuraya River in Echizen, with the honmaru, earthen ramparts, moat traces, gate foundations and corner turret sites still visible. The site is a Fukui Prefectural Historic Site; paths cross the earthworks, so expect uneven ground.

Excavations in the 1930s uncovered earthen structures and stone foundations that led to its official protection status at that time. This early archaeological work established the site as a recognized historic location.