Okuyama Barrier

The Okuyama Barrier (桥市 おくやま かいし) is a frontier fortification south of the city of Okuyama, Heisai Prefecture. The area is protected under law and contains various historical sites such as preserved farmhouses and a 16th-century manor which has been repurposed into the Okuyama Barrier Museum. 
== History ==
The barrier was constructed in the early 1300s by the Senyama clan to defend against hostile and invading Torima forces. The Barrier was the site of a number of skirmishes and sieges over the course of four centuries, eventually falling into disuse in the 1700s. In 1754, the Senyama chief Ogoyaka renovated and partially rebuilt Takahashi Castle, which sits around a mile north of the site. 
In traditional poetry and stories from Honzura, the Okuyama Barrier has often been used as a metaphor referencing determination, courage, and bravery. The phrase okuyama-kaishi wo mureru is a proverb meaning to maintain the Okuyama Barrier, and is used metaphorically to mean 'taking a stand' or 'holding a strong defence'.