ANALYSIS REPORTS IN THIS AREA
See the onsen of Kusatsu Onsen
Onsen analysis reports visualized by minerals, pH, temperature, and a 5-axis profile. Swipe to see other facilities.
Overview
The history of Kusatsu Onsen is ancient, with legends attributing its discovery to figures like Yamato Takeru no Mikoto or Minamoto no Yoritomo. During the Edo period, it was ranked as the top onsen in eastern Japan, solidifying its status as a premier hot spring destination. Today, it is celebrated alongside Arima Onsen and Gero Onsen as one of the "Three Famous Springs of Japan," beloved by spa-goers and tourists alike.
The "Yubatake" (hot water field) in the center of the town is the symbol of Kusatsu Onsen. It's a breathtaking sight, with about 4,000 liters of hot spring water gushing out every minute and flowing through wooden troughs. The billowing steam and the distinct smell of sulfur create an atmosphere unique to a top-tier onsen resort. At night, the Yubatake is illuminated, creating a magical scene.
Typical Spring Quality and Indications
The main spring quality of Kusatsu Onsen is its powerful "Acidic spring" (sansei-sen), one of the most potent in Japan. With a pH level of around 2.1, its acidity is extremely high, giving it exceptional sterilizing properties. This strong acidity is said to be effective for various skin conditions. The water also contains sulfur, which contributes to its characteristic aroma.
- Atopic dermatitis
- Psoriasis vulgaris
- Chronic eczema
- Cuts
- Peripheral circulatory disorders
Water Characteristics and Best Season to Visit
The source water temperature is extremely high, ranging from 51°C to 94°C (124°F to 201°F), making it too hot to bathe in directly. This led to the development of the "Yumomi" tradition, a cultural practice of cooling the water using long wooden paddles. Thanks to the abundant water volume, most inns and bathing facilities offer "gensen kakenagashi" baths—water flowing directly from the source without any added cold water or reheating.
Situated on a plateau at an altitude of about 1,200 meters, Kusatsu Onsen can be enjoyed year-round. In winter, you can soak in the hot springs while admiring the snowy landscapes, and in summer, it serves as a cool mountain retreat. The sight of steam rising against the snow in winter is particularly special.
Access
Facilities with Analysis Reports
Facilities Without Analysis Reports
Nearby Sightseeing & Local Cuisine
- Yubatake: The main hot spring source in the town center. The nightly illumination is a must-see.
- Yumomi and Dance Show (at Netsu no Yu): Watch and participate in the traditional water-cooling performance.
- Sainokawara Park & Open-Air Bath: A large park with a river of hot spring water and one of Japan's largest outdoor baths.
- Kusatsu Onsen Ski Resort: Enjoy skiing and snowboarding in winter.
- Onsen Manju: The classic onsen town snack. Try them freshly steamed.
- Maitake Mushroom Dishes: Tempura or mixed rice (kamameshi) featuring this local specialty.
- Okkirikomi Udon: A Gunma-prefecture specialty of wide, flat noodles stewed with vegetables.
References
Related Articles