Verified in Japan

Semboku, Akita / 玉川温泉

Tamagawa Onsen

A mountain hot-spring retreat known for Japan's most acidic spring water (pH 1.2, 98°C), with a 9,000-litre-a-minute source; day bathing 10:00-15:00, closed in winter.

Steam rising from a rocky volcanic slope, with a paved walkway and autumn trees
The steaming nature trail at Tamagawa Onsen (photo taken October 2017)Photo: Raita Futo / Wikimedia Commons, CC BY 2.0 (resized) · License · Source

Last official check

25 Sept 2026

Traveler reports

0

Reports open in Phase 2

Next scheduled check

24 Dec 2026

Decide before you go

A short summary made from the official facts below. Check the rows for details.

Getting there
Bus
Admission
Paid (see the price below)
Closing days
Closures change with the season

Before you go

Only facts we confirmed on official sources are shown. Anything else is listed under “Not yet confirmed”.

Opening hours

Day bathing 10:00-15:00 (last entry 14:30).

Checked 25 Sept 2026 on the official site
Closed

Closed in winter (November 30 to mid-April); the sister inn Shin-Tamagawa Onsen stays open.

Checked 25 Sept 2026 on a tourism board site
Admission

Day bathing: adults 1,000 yen, children 500 yen (from April 16, 2026).

Checked 25 Sept 2026 on the official site
Getting there

In the summer season (late April to late November) you can come by car, taxi or bus. Route 341 closes at night (19:00-8:00) just after it opens in spring and just before it closes in autumn.

Checked 25 Sept 2026 on the official site
Parking

Day visitors use the prefectural Tamagawa park car park on the way down to the inn (about 8:30-16:30, 300 yen per visit).

Checked 25 Sept 2026 on the official site
Not yet confirmed

Payment, Accessibility

we have not confirmed this on an official source yet. Check with the spot before you go.

Found wrong or outdated information? Let us know

Address: Semboku, Akita (Japanese address: 秋田県仙北市田沢湖玉川渋黒沢)

Official site: https://www.tamagawa-onsen.jp/

Location

Smaller pins are other spots nearby.

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Nearby spots

Distances are straight-line distances, not travel distances.

Crowds

Not yet confirmed

Crowd level, Best time to visit, Peak time, Busiest days, Busiest season

no official source yet, and not enough traveler reports.

Latest traveler report
None yet

Traveler crowd data by time of day appears after 5 traveler reports (0 so far).

You can check typical busy hours in Google Maps ("Popular times" on the place's page). Open this spot in Google Maps

Visiting respectfully

  • Local etiquetteBecause of bears, avoid going out at night or early morning and don't eat on the nature trail (natural bedrock bath area); carry a bear bell and walk in groups (bells and trekking poles are lent free).Checked 25 Sept 2026 on the official site
  • Local etiquetteThe main bath is built of Aomori hiba cypress with 11 kinds of baths; the 100% source-water bath is very strong.Checked 25 Sept 2026 on the official site

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