Tomioka Castle Ruins

Reihoku, Japan, Japan

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Tomioka Castle Ruins (Tomioka‑jō ato) are the remains of a hilltop castle located on the Tomioka Peninsula in Reihoku Town, Amakusa District, Kumamoto Prefecture, Japan, on a roughly 70‑meter‑high hill that is almost surrounded by sea on three sides and connected to the mainland only by a narrow strip of land, giving it strong natural defenses and a strategic position overlooking the approach to the Amakusa islands.

The castle was built between 1602 and 1605 by Terazawa Hirotaka (also called Terasawa Hirotaka) after he was awarded the Amakusa area following the Battle of Sekigahara, and it became known as the “Lying Dragon Castle” as a counterpart to Karatsu Castle’s “Flying Crane” motif, serving as a strong Shogunate outpost and a key defensive point in the early Edo period.

During the Shimabara Rebellion of 1637–1638, Tomioka Castle played an important role as a Shogunate stronghold that was attacked several times by Christian rebels and ronin from Shimabara and Amakusa; after nearby Hondo Castle was lost, surviving Terazawa samurai retreated to Tomioka and successfully repulsed repeated assaults, and the rebels eventually withdrew toward Hara Castle, making the siege a decisive moment in the rebellion.