Kusatsu Onsen
Japan's most celebrated hot spring resort — producing over 32,000 litres of acidic sulphurous water per minute from its collective springs, centred on the iconic Yubatake (hot water field). The water is so acidic (pH 2.1) that it kills almost all bacteria, giving rise to the local saying "the only thing Kusatsu water can't cure is a broken heart." The Yubatake at night is extraordinary.
1–2 days recommended
Public baths (Netsunoyu observation) ¥700
Village and Yubatake always accessible; Netsunoyu show: 6 performances daily (9:30, 10:00, 10:30, 15:30, 16:00, 16:30), closed Wed for experience only
Year-round (winter snow + steam is magical)
Bus from Naganohara-Kusatsuguchi Station (JR Agatsuma Line, 25 min from Takasaki)
Location
Why Visit
- 1
The Yubatake (hot water field) produces 32,000 litres of steaming water per minute — illuminated at night
- 2
pH 2.0 water kills virtually all bacteria and viruses — Japan's most powerful therapeutic spring
- 3
The Netsunoyu yumomi performance — wooden paddles stir the 98°C water to cool it for bathing
Local Tips
The Yubatake — a wooden channel of bright green hot spring water flowing through the centre of the village — is Kusatsu's iconic image. The Netsunoyu time-bath ceremony (short, theatrical, ¥700) is worth watching. The spring water is highly acidic — strong enough to dissolve metal over time, making it medically powerful but unusual. Arrive in the evening when lanterns light the Yubatake.
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