| Mihara Castle | |
|---|---|
三原城 | |
| Mihara, Hiroshima,Japan | |
 Foundations of the tenshu of Mihara Castle | |
| Site information | |
| Type | yamashiro-styleJapanese castle |
| Condition | ruins |
| Location | |
  Mihara Castle Mihara Castle Show map of Hiroshima Prefecture Mihara Castle Mihara Castle (Japan) Show map of Japan | |
| Coordinates | 34°24′4.62″N133°4′57.57″E / 34.4012833°N 133.0826583°E /34.4012833; 133.0826583 |
| Site history | |
| Built | 1567 |
| Built by | Kobayakawa Takakage |
| Demolished | 1873 |
Mihara Castle (三原城,Mihara-jō) was ahirajiro-styleJapanese castle located in what is today the city of Mihara inHiroshima Prefecture. Its ruins have been protected by the central government as aNational Historic Site since 1957.[1]
In 1552,Kobayakawa Takakage relocated his seat fromTakayama Castle toNiitakayama Castle.[2][3] Kobayakawa Takakage was the son ofMōri Motonari and over the next 20 years, theKobayakawa clan helped theMōri clan defeat theOuchi clan and theAmago clan to secure supremacy over theChugoku region of Japan. The Mōri entrusted the Kobayakawa with theSan'yo region, whereas Kobayakawa Takakage's elder brotherKikkawa Motoharu was entrusted with theSan'in region, and the Kobayakawa clan had a strong navy which enabled them to dominate theSeto Inland Sea. In 1567, Takakage newly built a new castle ten kilometers downstream from Niitakayama Castle, utilizing small islands at the mouth of Nuta River, and incorporating Sakurayama Castle, an older fortification which had been constructed by theYamana clan in the earlyMuromachi period. The new Mihara Castle was initially a naval base and was needed as the harbor at Niitakayama Castle was becoming silted. From 1580 to 1588, the castle was greatly expanded and modernized with multiple concentric enclosures and numerousyagura watchtowers. As it was located directly on the seashore, it appeared to be floating on the sea at high tide, so it is also calledFloating Castle (浮城,Uki-jō).
The Mōri and Kobayakawa eventually came into conflict withOda Nobunaga, and subsequently withToyotomi Hideyoshi. On Nobunaga's assassination in 1582, The Kobayakawa reached an accord with Hideyoshi, and Kobayakawa eventually became a vassal of Hideyoshi, who needed the Kobayakawa navy. Kobayakawa Takakage was awardedIyo Province inShikoku and laterChikuzen Province inKyushu. Together withKuroda Yoshitaka (Kanbe), he was one of Hideyoshi's most trusted military advisors. In 1595, Kobayakawa Takakage turned his estates in Chikuzen to his adopted son Hideaki, and retired to Mihara Castle. During the reconstruction of Mihara Castle, the stone walls and structures of Niitakayama Castle were gradually dismantled as building materials, and most of thejōkamachi was relocated to Mihara. The presenttenshu foundation base dates from this reconstruction. At its height, the castle extended from the Akuhara River (Wakuhara River) in the east for about one kilometer to present-day Nishimachi to the west, and about 600 meters from the foot of Mt. Sakura in the north to Umanokuchi in the south. It had 32 corneryagura and 14 gates. The base of the tenshu was on the same scale as that ofEdo Castle; however no tenshu was actually built. Contemporary drawings show three double-story interconnectedyagura located on the base; however, one theory states that a three-story tower was relocated to Mihara Castle in 1615 from Tomojo Castle, after that fortification was destroyed in accordance with the shogunate's "One-Country One-Castle" decree.
The castle's fortifications were situated so that they encompassed the east-west route of theSanyōdō highway, forcing travelers to traverse a narrow route between stone walls with many rivers and moats blocking the way. Due to its position on the border betweenAki Province andBingo Province, it was the most important eastern stronghold for the Mōri clan.[4] Takakage died of illness at Mihara Castle in 1597. After the 1600Battle of Sekigahara, the newTokugawa shogunate assigned Aki and Bingo Provinces toFukushima Masanori. Masanori madeHiroshima Castle his seat, using Mihara Castle as a secondary stronghold. In 1619, the castle was reassigned to theAsano clan, who replaced Fukushima Masanori at Hiroshima. It continued to be used as a branch castle ofHiroshima Domain until the end of the Edo period. During this period, the Honmaru Palace was rebuilt in 1663. In 1707, stone walls were repaired due to the effects of the1707 Hōei earthquake. In the mid-Edo period.
After theMeiji Restoration, the castle grounds were secured by the government for the construction of theJapanese Imperial Navy Saikai Naval Base; however, this plan was canceled due to concerns about the sedimentation of the Nuta River. The remaining castle buildings and trees were put up for auction, and most of the buildings were disposed of as lumber. In 1894, during the construction of theSanyō Railway'sMihara Station on the castle grounds most of the stone walls were removed as materials for the construction of Itozaki Port.Land reclamation, especially for the construction ofJapan National Route 2 moved the castle further from the seashore. With the expansion and elevation of Mihara Station for theSanyo Shinkansen in 1975, the castle grounds were further divided. At present all that remains is the tenshu foundation, some disconnected remnants of stone walls and moats and the foundations of a gate and couple ofyagura. The remaining ruins are preserved as a park.[5] The base of thetenshu still stands and it is possible to stand on it and get a good view of Mihara City.
The castle was listed as one of theContinued 100 Fine Castles of Japan in 2017.[6]
