Gunma · Town

Kusatsu

草津町くさつまちKusatsu-machi

Japan's classic highland hot-spring town

Kusatsu is a hot-spring town at about 1,200 m on the eastern slope of the volcano Kusatsu-Shirane in north-western Gunma. Its Kusatsu Onsen, fed by strongly acidic springs with one of the largest natural flows in Japan, has been counted among the country's most famous spas since the Edo period.

Overview

Kusatsu sits on a volcanic plateau below Kusatsu-Shirane, an active volcano whose crater lake Yugama is one of the most acidic lakes in the world. Its springs emerge at temperatures up to about 95 °C and flow through the town centre in quantities larger than any other naturally flowing hot spring in Japan. The water is so acidic that it is said to dissolve a one-yen coin within days, and it has long been valued for skin complaints and as a 'finishing' bath after other spas.

The heart of the town is the yubatake, the 'hot-water field', a steaming cascade of wooden channels in the main square where the spring water cools and deposits yellow yunohana (sulphur flowers). Around it, a compact old town of inns, souvenir shops and public baths climbs the hillsides. The traditional method of cooling the water without dilution, yumomi – stirring it with long boards while singing the Kusatsu-bushi folk song – is performed for visitors.

In the Meiji era the German physician Erwin Bälz, a professor at the University of Tokyo, praised Kusatsu's water and climate and helped establish its modern reputation. Today it is a year-round resort with skiing in winter, hiking in the green season and a summer international music festival.

Landmarks

Yubatake
湯畑Yubatake
The steaming source in the main square, where hot water runs through wooden troughs and falls in a turquoise cascade; illuminated at night.
Netsu no Yu
熱乃湯Netsu no Yu
Hall on the yubatake where yumomi performances with the Kusatsu-bushi song are held several times a day.
Sainokawara Park
西の河原公園Sainokawara Kōen
Valley of steaming springs and green pools west of the centre, with one of Japan's largest open-air baths.
Otaki no Yu
大滝乃湯Ōtaki no Yu
Large public bathhouse offering baths of different temperatures in the manner of the old timed-bath cure.
Kosen-ji
光泉寺Kōsen-ji
Temple on the hill above the yubatake, traditionally founded by Gyoki, with a view over the square.
Bälz Memorial Museum
ベルツ記念館Berutsu Kinenkan
Museum on the life of Erwin Bälz and his work on Kusatsu's springs.

Districts

Yubatake area
湯畑Yubatake
The town centre around the source, with inns, public baths and shops selling onsen manju.
Sainokawara-dori
西の河原通りSainokawara-dōri
Shopping street leading from the yubatake down to the Sainokawara park.
Jizo area
地蔵Jizō
Quiet upper quarter around the Jizo no Yu spring, with small inns and a traditional bathhouse.
Tenguyama
天狗山Tenguyama
The ski area and green-season plateau on the slopes above town.

History

Legends credit the discovery of the springs to the prince Yamato Takeru or to the monk Gyoki in the eighth century, and claim that Minamoto no Yoritomo bathed here in 1193. By the Sengoku period Kusatsu was known across Japan, and in the seventeenth century the Confucian scholar Hayashi Razan named it with Arima and Gero as one of the country's three famous hot springs.

In the Edo period visitors came for jikan-yu, a strictly timed hot bathing cure supervised by bath masters. The springs also attracted people with Hansen's disease, who formed a community in the Yunosawa district; the national sanatorium Kuryu Rakusen-en was built nearby in 1932. The narrow-gauge Kusakaru electric railway linked Kusatsu with Karuizawa from 1926 to 1962. In 2018 a phreatic eruption at Motoshirane, a peak of Kusatsu-Shirane, reminded the town of the volcano above it.

8th century
Legend has the monk Gyoki discover the springs.
1193
Minamoto no Yoritomo is said to have bathed at the spring later called Shirahata no Yu.
17th century
Hayashi Razan names Kusatsu, Arima and Gero as Japan's three famous hot springs.
1870s–1880s
Erwin Bälz studies and promotes Kusatsu's springs and climate.
1926
The Kusakaru electric railway from Karuizawa reaches Kusatsu; it closes in 1962.
1932
The national sanatorium Kuryu Rakusen-en opens.
1980
The Kusatsu Summer International Music Academy and Festival is founded.
2018
A phreatic eruption at Motoshirane affects the Kusatsu ski area.

Culture

Kusatsu's bathing culture has its own rituals: yumomi, the stirring of water with wooden boards to the rhythm of the Kusatsu-bushi, and jikan-yu, the timed cure in which bathers enter very hot water together on command. The German physician Erwin Bälz is honoured as a benefactor, and the town is twinned with his birthplace, Bietigheim-Bissingen. In August the Kusatsu Summer International Music Festival brings classical musicians and masterclasses to the town.

Festivals

Kusatsu Summer International Music Festival
草津夏期国際音楽アカデミー&フェスティヴァルKusatsu Kaki Kokusai Ongaku Akademī ando Fesutivaru
Concerts and masterclasses of classical music held every August since 1980.
Yumomi performances
湯もみyumomi
Daily shows at Netsu no Yu in which women in cotton kimono stir the water with boards and sing Kusatsu-bushi.

Food

Onsen manju
温泉まんじゅうonsen manjū
Brown-sugar steamed buns with bean paste, sold hot along the streets around the yubatake.
Onsen tamago
温泉たまごonsen tamago
Eggs slowly cooked in the hot spring water until the yolk sets before the white.
Hanamame
花豆hanamame
Large runner beans grown in the cool highlands and simmered sweet.
Maitake soba
舞茸そばmaitake soba
Buckwheat noodles with maitake mushroom tempura, a staple of the town's restaurants.

Getting around

From Tokyo, take the JR Agatsuma Line (limited express Kusatsu from Ueno, or via Takasaki) to Naganohara-Kusatsuguchi, then a bus of about 25 minutes up to Kusatsu Onsen bus terminal.
Direct highway buses run from Shinjuku and other Tokyo terminals in about four hours.
Buses also connect Kusatsu with Karuizawa, about 75 minutes away, for Shinkansen connections on the Hokuriku line.
The town centre is compact and walkable; roads towards Kusatsu-Shirane and Manza may be closed depending on the volcanic alert level – see the JMA and town websites.

Day trips

Kusatsu-Shirane and Yugama
湯釜Yugama
Acidic turquoise crater lake in Joshin'etsu Kogen National Park; access depends on current volcanic restrictions.
Mount Asama and Onioshidashi
鬼押出し園Onioshidashi-en
Black lava field from the 1783 eruption of Asama on the Tsumagoi plateau.
Karuizawa
Highland resort in Nagano with forests, churches and outlet shopping.
Manza Onsen
万座温泉Manza Onsen
Milky-white sulphur springs at about 1,800 m on the far side of the volcano.

Other cities in the prefecture

CapitalMaebashiMaebashi-shiSilk, canals and poetry below Mount Akagi Core cityTakasakiTakasaki-shiDaruma dolls and the crossroads of Gunma

Frequently asked questions

Why is Kusatsu Onsen so famous?

For its large natural flow of very hot, strongly acidic water, its picturesque yubatake and its long history: it has been considered one of Japan's three great hot springs since the Edo period.

What is yumomi?

A traditional way of cooling the very hot spring water without diluting it: people stir the bath with long wooden boards while singing the Kusatsu-bushi. Shows are held at Netsu no Yu.

Is Kusatsu's water safe for everyone?

The acidic water can irritate sensitive skin and eyes; it is advisable to keep baths short, avoid getting water in the eyes and rinse off afterwards if the skin reacts.

How do I get to Kusatsu from Tokyo?

By train on the JR Agatsuma Line to Naganohara-Kusatsuguchi and then by bus, in about three hours in total, or by direct highway bus from Shinjuku in about four hours.

Can Kusatsu be combined with Karuizawa?

Yes. Buses link the two in a little over an hour, and Karuizawa has Shinkansen connections to Tokyo.

Sources

1.草津町ホームページ (opens in a new tab) — 草津町 (Kusatsu Town)
2.気象庁ホームページ（火山情報） (opens in a new tab) — 気象庁 (Japan Meteorological Agency)
3.上信越高原国立公園 (opens in a new tab) — 環境省 (Ministry of the Environment)
4.Japan National Tourism Organization (opens in a new tab) — JNTO