Mihara Castle was located in present-day Mihara City, Hiroshima Pref. The castle ruin is a designated National Historic Site. It was built on the island near the river mouth of the Numata River in 1580 by Kobayakawa Takakage, a son of Mori Motonari. As the castle looked as if it were floating on the sea, it was called “Uki-shiro (floating castle)” or “Umi-shiro (sea castle).” The castle area was about 900 m from east (the Wakuhara River) to west (where Garyu Bridge is presently located) and about 700 m from north to south. Mihara Castle was an important fort, and it is said that Toyotomi Hideyoshi once stayed here. After Takakage’s death, Asano Tadayoshi, the head retainer of the Asano clan, who fought for the Toyotomi forces in the Battle of Sekigahara, was transferred to this castle. The castle was used as a branch castle of the Hiroshima domain until the end of the Tokugawa Shogunate. It was dismantled in 1871, when the domain system was abolished by the Meiji government. Now the castle area is arranged into a park, where the stone walls and moats remain.
- Shiro-machi, Mihara, Hiroshima Prefecture 723-0014
- Mihara Castle Ruins