# Kawayu Onsen

> A riverside hot spring near Kumano Hongu where hot water wells up through the gravel of the Ōtō River, so visitors can scoop out their own open-air bath; in winter a huge communal 'Sennin-buro' is dammed up for free bathing.

- Prefecture: Wakayama
- Type: Onsen
- Address: Tanabe, Wakayama, Japan
- Admission: Free
- Official site: https://www.hongu.jp/onsen/kawayu/

At Kawayu Onsen hot water rises straight through the pebbly bed of the Ōtō River, so with a small spade and a swimsuit you can dig a hollow at the water's edge and mix river water to your preferred temperature for a genuinely wild open-air soak. From December to late February, when the river runs low, the town dams a broad section of the riverbed to create the Sennin-buro, a vast communal bath said to hold a thousand people, open free of charge and lit at night. Because it is a river, bathing requires a swimsuit, and soap and shampoo are not allowed. The spring lies a short distance from Yunomine and Kumano Hongu, and riverside inns line the bank.

## FAQ

### When can I use the Sennin-buro communal bath?

The large dammed-up Sennin-buro operates only from December to late February, is free to use and needs a swimsuit. Outside that season you can still dig your own small bath in the riverbed.

### Do I need a swimsuit at Kawayu Onsen?

Yes. Because the bath is in an open river, a swimsuit is required, and soap or shampoo may not be used. Bring a towel and, if you want to dig a pool, a small spade.

---
Source: Kawayu Onsen — Japan Voyage