The Historic Site Osarizawa Mine, designated as a Modern Industrial Heritage site, is said to have been opened approximately 1,300 years ago. Inside the tunnel, bedrock dating back about 9 million years is exposed, allowing visitors to closely experience the remains of what was once one of Japan’s largest copper vein mining sites. It is also said that gold produced at the Osarizawa Mine was used for the Konjikidō Hall of Chūson-ji Konjikidō in Hiraizumi and for the Great Buddha of Tōdai-ji Daibutsu in Nara.From April 2026, the site will operate as a social studies field trip facility and will be open by advance reservation only.