Nagurumi Castle Ruins Information Center

Minakami, Japan, Japan

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Nagurumi Castle was originally built by the Numata clan at the end of the 15th century as a defensive fortification over a strategic location in what is now Minakami, Gunma Prefecture, Japan.

In the 16th century, under the direction of Sanada Masayuki, a general of the Takeda clan, the castle became a key base for expanding Takeda's influence, used as a bridgehead to capture Numata Castle. Nagurumi Castle played a pivotal role in the military conflicts of the era, especially during the struggle between the Takeda, Hojo, and Toyotomi forces.

In 1589, the Hojo clan unexpectedly seized Nagurumi Castle after a surprise attack while the commander was absent, an event which contributed to the later Siege of Odawara and the fall of the Hojo clan, marking a critical step toward the unification of Japan under Toyotomi Hideyoshi.

Though the castle was abolished afterward, its ruins remain, with stone and earthworks still visible today, illustrating its historical significance in the Sengoku period power struggles.