The date of construction is unknown but it is known that the castle existed prior to the Nanbokucho Period. In 1532, the Amago Clan from Izumo attacked Mimasaka Province and took control of the castle. In 1566 the Mori Clan defeated the Amago to become the rulers of the entire Mimasaka Province.
Ukita Naoie attacked the castle in 1580 but was forced out by the Mori. In 1582 the Mori Clan and Hashiba Hideyoshi reached an agreement to transfer control of the area to Ukita Uji. The citizens were so loyal to the Mori Clan that they refused to accept their new leader. They had to be convinced by Mori Terumoto that the transfer of power had indeed been decided. Soon after the transfer of power however, the castle was abandoned.
From Mimasaka-Takio Station (Inbi Line) walk straight out and turn right where the road ends. Continue walking until you reach a bridge. Cross the bridge. From the bridge there are signs directing you toward the trail entrance. It's about 15 minute walk from the station to the trail entrance. From there, it takes about 25 minutes to reach the top. It seems best to come in winter to avoid all the plants that cover the trail in the summer which can make it dangerous as you can't see if you're stepping on solid ground. It's best to take one of the sticks at the trailhead.
|English Name||Ioyama Castle|
|Alternate Names||Ioyamajo (祝山城), Iwaoyamajo (岩尾山城)|
|Year Founded||Unknown (Before Nanbokucho Period)|
|Castle Condition||Ruins only|
|Designations||Local Historic Site|
|Historical Period||Pre Edo Period|
|Main Keep Structure||None|
|Access||Mimasaka-Takio Station (Inbi Line), 15 min walk|
|Visitor Information||Always open/none|
|Website||http://www.okayama-kanko.jp/modules/kankouinfo/pub kihon detail.php?sel id=1091&sel data kbn=0|
|Location||Tsuyama, Okayama Prefecture|
|Coordinates||35° 7' 42", 134° 3' 46"|
|Year Visited||Viewer Contributed|