It is said that the Oga Onsenkyo Village ( Yumoto Onsen and Ishiyama Onsen) was discovered during the Daido Period (806-810) by Sakanoue no Tamuramaro, and the first records of people bathing in it date from the Edo Period.
Through the Meiji and Taisho Eras, Ishiyama Onsen was called Ishiyama Stone Mountain Mine before it had flourished as a onsenkyo village around 1955. At this place, limestone had mined in the way of open-air digging for selling to Ani and Hanaoka region.
Oga Hot Springs Village opened in 1955. Through the Meiji and Taisho Eras, it was known as Stone Mountain Mine and is said to have been the site of open-air digging for limestone used in gold and silver solvent. It is said that the hot spring was discovered long ago during the Daido Period (806-810) by Sakanoue no Tamuramaro, and the first records of people bathing in it date from the Edo Period.
