This complex is located in the Yakeyama area, the gateway to the Oirase Stream. The Oirase Keiryu Museum and Oirase Yusui Museum are adjacent to each other. Inside the Oirase Keiryu Museum, there are free exhibits about the nature of the Oirase Stream, a souvenir and local product sales area, and the “Oirase Moss Ball Workshop” where you can experience making moss balls. Meanwhile, the Oirase Yusui-kan houses a workshop space where Oirase Genryusui, Oirase's drinking water, is produced, and on the second floor is the base office of Green House, which operates various nature experience tours. This facility also provides tourist information about the Oirase Stream, so when visiting the Oirase Stream, we recommend stopping here to get various information and precautions before heading out.