6. Oirase RiverAomori Prefecture The Oirase River is a river located in eastern Aomori prefecture, in the Tōhoku region of northern Japan. The Oirase River is the only river draining Lake Towada, a large caldera lake on the border of Aomori and Akita Prefectures. The river flows in a generally eastern direction, through the municipalities of Towada, Rokunohe, Oirase and Hachinohe before exiting into the Pacific Ocean. The upper reaches of the river form a scenic gorge with numerous rapids and waterfalls, and is one of the major tourist attractions of the Towada-Hachimantai National Park. The lower reaches of the river are used extensively for irrigation. In 1996 the sound of flowing water at the Oirase River was selected by the Ministry of the Environment as one of the 100 Soundscapes of Japan. From Wikipedia, the free encyclopedia.