It is a quiet onsen area in the mountains north of Mt. Aso, near the border of Oita Prefecture. It is one of the most popular onsen hot springs in Japan. Twenty-four small Japanese-style inns line the Tanohara River. The area operates under the cooperative policy of “the whole area as one inn.” Big hotels and flashy signboards are not allowed. The area successfully creates a peaceful, rustic onsen resort atmosphere. This is why Kurokawa is very popular.

Each inn has its own onsen source with a different type of onsen water. If you buy an onsen pass made of hinoki cypress for 1,300 yen, you can visit three onsen inns and enjoy their baths.

The “Yuakari” event at night during winter is very attractive. Bamboo lanterns are placed along the stream, mystically illuminating the onsen area.

Successful Kurokawa now serves as a good example to other onsen areas losing popularity. Some have begun to adopt the idea of the onsen pass.