A Historic Post Town on the Aizu-Yonezawa Highway
A Hot Spring and Mountain Salt Formed by 15-Million-Year-Old Green Tuff
The Ōshio area is a region where nature and history blend harmoniously.
Geologically, it features formations such as the Gomaisawa River Layer, composed of submarine volcanic ejecta from about 15 million years ago, as well as unique rock formations like Kagura Rock and Tengu Stone, which consist of dacite from around 14 million years ago. The area is also characterized by green tuff. Natural hot springs emerge within the region, and there are sites like the Onsen Shrine and a mountain salt production facility.
Historically, the Ōshio district is of great significance, as it is home to the ruins of Kashiwagi Castle, which was developed by the Aizu Ashina clan during the Sengoku period. The Aizu-Yonezawa Highway also passed through this area, making it a thriving post town during the Edo period.
Even today, the area is cherished as a place where a rich natural environment coexists with historical heritage.