Along the Oto River, a tributary of the Kumano River, is a simple hot spring with a series of inns, restaurants, and public bathhouses on the north bank.
The 500 meter section of the Oto River in this area is a rare spot where hot spring water springs from the bottom of the river.
If you dig in the sand of the riverbed, hot spring water springs up instantly, and you can create your own original open-air bath by digging with a shovel.
During the day, visitors can play in the river and soak in the hot spring while enjoying the view of the rich nature,
At night, you can enjoy the moon on a stone pillow and listen to the murmuring of the river while soaking in the hot spring water.
The hot spring water is sodium bicarbonate and chloride hot spring.
The spring water is over 73°C, and the river water mixes with it to create a moderate hot spring.
The hot water is also gushing into the river stream, and bubbles can be seen rising from the river bottom.
During the winter season, when the river's flow rate is lowered, a giant open-air bath called "Senjin-buro" is created by holding back the river.
Each ryokan also has a simple enclosure on the riverbank, allowing visitors to enjoy the atmosphere typical of Kawayu.
Approximately 60 minutes from Shingu Station on the Kisei Main Line by Kumano Gobo Nankai Bus and Yagi Shingu Express Bus of Nara Kotsu
Yagi Shingu Express Bus of Nara Kotsu from Kintetsu Yamato Yagi Station via Kintetsu Takada-shi Station, Kintetsu Gosho Station, and Gojo Station on JR Wakayama Line (about 5 hours and 30 minutes from Yamato Yagi Station)