Yamagata · Zao Onsen
Zao Onsen Kawarayu Public Bath
蔵王温泉 川原湯共同浴場
One of the three public baths of Zao Onsen, set quietly up the Yu-no-Ka lane. It is a 'foot-of-the-spring' bath where water rises directly beneath the slatted floor, with no added water and no recirculation — a full flow-through. Open 6:00–22:00 with no closing day, it is unmanned: you put ¥300 (¥100 for children) in the box at the entrance. There are no showers or taps, only a rinse before entering, but the strongly acidic sulphur spring is exactly as it comes from the ground. It is run by the Zao Onsen tourist association, and inns in Zao sometimes hand out free bathing vouchers.
- Price (adult)
- ¥300
- Hours
- 06:00–22:00
- Closed
- Open daily
- Access
- 40 minutes by Sankō bus for Zao Onsen from Yamagata Station on the JR line, alighting at Zao Onsen Bus Terminal, then 7 minutes on foot along Yu-no-Ka lane
- Water type
- Sulfur spring
- Tattoos
- Ask ahead
- Admission
- Adults ¥300, children ¥100. It is unmanned: you put the money in the box at the entrance, with no change given and no card payment. Bring coins. Guests staying at inns in Zao are sometimes given bathing vouchers to drop in the box instead.
- Spring water
- An acidic sulphur-bearing aluminium sulphate-chloride spring (hypotonic, acidic, high-temperature), with pH dropping to around 1. It is bluish-white and turbid with a clear sulphur scent, and runs hot. Metal jewellery must come off, and cuts will sting.
- Baths
- There is only a rinse ladle area, with no showers or taps. Each side has one tub, and the space, with its changing room, is plain and largely timber. The spring rises directly beneath the slatted floor of the bath, so the water reaches the tub without meeting air.
- How it works
- The routine is simple: put ¥300 in the box at the entrance, undress, rinse with the ladle water and step into the tub. As the water is hot, testing it with your feet first is safer. There is no soap or shampoo, so washing properly means using another facility in the spa town.
- Access & parking
- About 7 minutes on foot from Zao Onsen Bus Terminal, up and back along Yu-no-Ka lane. The three public baths — Kamiyu, Shimoyu and Kawarayu — are 3 to 5 minutes apart, so all can be done in one round. There is no dedicated parking, so use the paid lots in the spa town. In winter, with heavy snow, allow extra time to move about.
- Phone
- 023-694-9328
- Official site
- zaomountainresort.com ↗
- Open in Google Maps
- Google Maps ↗
Essentials
Stay in this onsen town
Compare and book stays in Zao Onsen. Day bathing itself needs no booking.
Opens partner booking site (affiliate)
Why go
- Spring rising beneath the slatted floor
- Full flow-through with no added water
- An unmanned bath for ¥300
300 yen for water welling up beneath the slats
Kawarayu is one of the three public baths of Zao Onsen, set a little further back than the other two and therefore quiet. Its defining feature is that the spring rises directly beneath the slatted boards of the bath floor — an arrangement called 'rising at the foot', where the water enters the tub without meeting air, so it oxidises little and stays fresh. With no added water and no recirculation, it is a full flow-through, and the place to taste Zao's strongly acidic sulphur spring most directly. The fee is ¥300 for adults, dropped in the box at the entrance.
Using it knowing there are no wash stations
Kawarayu has neither showers nor taps. Near the entrance there is a rinse area, where you ladle water over yourself before stepping into the tub. There is no soap, shampoo or dryer, so it is best thought of as a place to soak rather than to wash. Like Zao's other public baths the water runs hot, and the degree of turbidity changes through the day. It therefore suits a short soak while walking the spa town rather than washing up and resting on the first day of a trip. The three baths are 3 to 5 minutes apart, so they can be compared in a single round.
Three public baths: how to divide them
Zao's public baths are Kamiyu, Shimoyu and Kawarayu, all at the same price and hours (¥300 for adults, 6:00–22:00, no closing day). What differs is the character of the water and the atmosphere. Kamiyu sits at the centre of the spa town and is the easiest to use; Shimoyu is closest to the bus terminal with a footbath beside it; Kawarayu is furthest back and uses the spring rising beneath the bath floor. All three can be done in a day, but since the water is strongly acidic and hot, splitting into two visits puts less strain on the body.
Before you go
- No official tattoo policy is published — ask at reception.
- As a communal bath there is no soap or shampoo — bring your own or buy at the shop.
- The water runs hot (43–45°C). Don't add cold water; take short repeated dips instead.
- Payment is usually by ticket machine in cash — bring coins.
- Last entry is 30–60 minutes before closing.
Features
Mood & scenery
Price
Who with
Amenities
✔ Verified operating: 2026-10 Operating status and rates cross-checked against the official site and onsen guides (full source notes in Japanese on the JA page)
Prices and hours change. Check official sources before visiting.
More in this area
Zao Onsen Dai-Rotenburo
A terraced open-air bath along a mountain stream that holds 200 people, with bluish-white strongly acidic sulfur water. Open late April to late November only; closed in winter. Summer starlight sessions at night.
Shirogane-yu (Ginzan communal bath)
A Kengo Kuma-designed communal bath at the entrance to Ginzan's Taishō-era street. Hot water with drifting mineral flakes for ¥500. The one place day visitors can bathe in Ginzan's water — reception closes at 3:30 pm.
Zao Onsen Kamiyu Public Bath
A log-cabin-style communal bath at the top of Takayu-dōri. Zao's three public baths (Kamiyu, Shimoyu, Kawarayu) all cost ¥200, paid into an honesty box. No washing stations — just rinse and sink into the strongly acidic milky sulfur water.
