Yamagata · Zao Onsen
Zao Onsen Shimoyu Public Bath
蔵王温泉 下湯共同浴場
A wooden public bathhouse in the heart of Zao Onsen in Yamagata City, a spa said to have been opened 1,900 years ago. Zao has three communal bathhouses - Kamiyu, Kawarayu and Shimoyu - long used by locals and long-stay cure guests. Zao's water is among Japan's most strongly acidic sulfur springs (around pH 1); Shimoyu blends the Jaaragawa-Orikuchi, Inkyo and Kaminokawa sources in full free-flow. Because the water barely meets air, it stays clear rather than milky. An unmanned style - drop coins in the red box at the entrance - with simple gender-separated indoor tubs, no showers, just ladle-water for rinsing. At 300 yen it delivers Zao's intense spring water straight, and many rate it the most quintessentially Zao of the three bathhouses. A lukewarm footbath adjoins. About 3 minutes on foot from the Zao Onsen Bus Terminal, open 6:00-22:00 year-round.
- Price (adult)
- ¥300
- Hours
- 06:00–22:00
- Closed
- Open daily
- Access
- 30-2 Zao Onsen, Yamagata, Yamagata (postal code 990-2301). About 3 minutes on foot from the Zao Onsen Bus Terminal (Sanko Bus). No dedicated parking - use nearby lots. Inquiries: Zao Onsen Tourist Association, 023-694-9328.
- Water type
- Sulfur spring
- Tattoos
- Ask ahead
- Phone
- 023-694-9328
- 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
- One of Japan's most acidic sulfur springs (around pH 1) for 300 yen - a 3-source blend in full free-flow
- Unmanned: drop coins in the red box; indoor tubs only, no showers - pure old-cure-spa simplicity
- 6:00-22:00, open daily, with a lukewarm footbath; 3 minutes from the Zao Onsen Bus Terminal
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
Price
Mood & scenery
Who with
✔ 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.
