Niekawa-no-Yu Public Bath

4.4★ · 390 Google ratings · Kusatsu, Gunma · 煮川乃湯（共同浴場）

Open in Google Maps Official site (Japanese)

✓ Natural hot-spring water✓ Free-flowing source water

Before you go

Can you bathe here?

Day visitors

✓ YesOpen to tourists 24 hours if manners are respected, though one visitor described unfriendly treatment from a local.stated by 5 visitors · Oct 2025 – Aug 2026

Hours

00:00–24:00from the facility listing

Price

FreeFree unattended public bath with no fee box, occasionally a donation ask.stated by 6 visitors · Jan 2026 – Aug 2026

Private bath

NoSmall shared, gender-separated communal bath, not private.stated by 2 visitors · Oct 2025 – Jun 2026

Bathing arrangement

Men and women separateGender-separated changing rooms and bathing rooms.stated by 2 visitors · Oct 2025 – Jun 2026

Tattoos

Not known · call aheadno policy stated in the 44 recent reviews we read or on the facility's website

How we know this

Watch out

Bath temperature

Reviewers consistently report scalding water in the 46-50C range, with 47C cited most often.

stated by 6 visitors · Aug 2025 – Aug 2026

Soap & shampoo

No amenities and often no washing area at all, just the hot tub itself.

stated by 2 visitors · Oct 2025 – Jun 2026

Water added

Water is never diluted, which is exactly why the bath runs dangerously hot.

stated by 2 visitors · Oct 2025 – Aug 2026

The bath

What you’ll find

A tiny, free, unmanned communal bathhouse in Kusatsu fed straight from the Niekawa source, famous for scalding 46-50C water that most visitors can only enter for seconds at a time.

Outdoor bath

NoDetailed description covers only a small indoor tub and washroom, no outdoor bath mentioned.stated by 1 visitor · Jun 2026

Indoor baths

1One small indoor tub per gender-separated bathing room.stated by 1 visitor · Jun 2026

Sauna

NoFacility is a single small tub room with no amenities of any kind, no sauna.stated by 1 visitor · Jun 2026

The water

Free-flowing (kakenagashi)

✓ Yes100% source-fed flow-through bath just meters from the spring itself.stated by 3 visitors · Aug 2025 – Dec 2025

Spring type

Acid sulfur-aluminum-sulfate-chlorideStrongly acidic sulfur-aluminum-sulfate-chloride spring, cited as some of the best water quality in Kusatsu.stated by 3 visitors · Sep 2025 – Aug 2026

Source temperature

48.8°COfficial 2023 spring analysis cited by one reviewer puts the source at 48.8C.stated by 1 visitor · Jun 2026

Bath temperature

47°CReviewers consistently report scalding water in the 46-50C range, with 47C cited most often.stated by 6 visitors · Aug 2025 – Aug 2026

pH 2.1Official spring analysis quoted by one reviewer gives a strongly acidic pH of 2.1.stated by 1 visitor · Jun 2026

Water added

NoWater is never diluted, which is exactly why the bath runs dangerously hot.stated by 2 visitors · Oct 2025 – Aug 2026

Practical

What to bring

Soap & shampoo

Not provided — bring your ownNo amenities and often no washing area at all, just the hot tub itself.stated by 2 visitors · Oct 2025 – Jun 2026

Guide

What visitors add

The water

The water is extremely hot: 37 of 44 text reviews mention the heat, with reviewer temperature estimates ranging from about 43°C to nearly 50°C (e.g. '47°C on average', '49 degrees near the source', '46 degrees near the inlet'); multiple reviewers could only stay in for seconds.

stated by 37 visitors · Jul 2025 – Aug 2026

Price

Admission is free; 12 distinct reviews describe it as a free communal bath, and one reviewer notes there is not even a donation box.

stated by 12 visitors · Aug 2025 – Jun 2026

For foreign visitors

Ten distinct reviews discuss tourist access: the clear majority say tourists may use this bath (one notes it is not one of Kusatsu's three officially tourist-designated public baths, but is in practice open to visitors without restriction), while one reviewer reports being harassed by a local elderly man over shoe placement and manners. Several reviews stress following local manners (no photography inside, do proper kakeyu, bring a towel).

stated by 10 visitors · Sep 2025 – Aug 2026

Day-use visits

Three distinct reviews indicate the bath is usable around the clock (24 hours, day and night); one reviewer bathed at 1am on a weekday, another at 6:45am.

stated by 4 visitors · Aug 2025 – Jun 2026

The water

The spring is a strongly acidic sulfur spring from the Nikawa source; one reviewer cites the 2023 (Reiwa 5) analysis: 48.8°C at source, pH 2.1, acidic aluminum-sulfate-chloride sulfur spring; four distinct reviews describe acidic/sulfurous, high-quality water.

stated by 4 visitors · Sep 2025 – Aug 2026

Towels, soap & lockers

Three distinct reviews report no amenities, no lockers, and no washing stations: only shelves/baskets in the changing room (bring your own towel and leave valuables at your hotel or car; a plastic drawstring bag is provided to carry valuables into the bathing area). One reviewer separately reports losing a wallet left behind.

stated by 4 visitors · Sep 2025 – Jun 2026

Timing