Hiruzen is the name of an area located in northern Okayama Prefecture on the border of Daisen Oki National Park, known for its spectacular natural beauty. Its main features are Hiruzen Sanza, a mountain range with three peaks more than 1,000 m high, and Hiruzen Highland, a plateau at an elevation of 500 m. The mountains are dormant volcanoes. In winter, the area is covered in snow.

The highland is a popular resort area with summer attractions such as Hiruzen Jersey Land, the largest Jersey cattle ranch in Japan producing excellent cheese and ice cream. Sheep are also raised, and the mutton dish called Genghis Khan is popular. Hiruzen Horse Park offers horse riding. There’s also a winery and an English-style flower garden. The mountain peaks are popular for hiking. In winter, Hiruzen becomes a snow resort.

Hiruzen was settled from the Japanese stone age and there are many remains from the Jōmon and Yayoi periods, including kofun burial mound groups.