Zao Onsen Dairotenoburo is a large outdoor hot spring bath located in Zao Onsen, Yamagata Prefecture. Situated at approximately 1,000 meters above sea level in a mountainous area along a mountain stream, it was completed in 1987. Known as a rustic outdoor bath where visitors can drop by casually even empty-handed, guests can enjoy the happiness of soaking in 100% source hot spring water while feeling the crisp highland air and listening to the babbling of streams and chirping of wild birds. The facility utilizes hot springs from 5 different sources with an impressive flow rate of 573 liters per minute. It features separate male and female outdoor baths with large stone-built bathing areas that can accommodate approximately 200 people at once.