Koyunuma

916. Koyunuma, Niseko, Hokkaido ★ A wild onsen. In early April it was snowy, so we used snowshoes to get there normally. From Hokkaido Rd 66, which is closed to cars during the snowy season, we had to follow the map through snow and trees to the source. The total walk from the road took about 15 minutes, and from around the middle of the route we could already see the lake in the low ground, surrounded by snow. In the low ground there is a lake, and inside it jets of onsen water spring up in different places. In this way the whole lake becomes an onsen. Nearby there is a shallow, shaped oval bath-puddle, and a blurred bath with its own source jet that flows into the onsen lake. A very strong sulfurous rotten smell. The water temperature varies a lot according to the information available. In winter it is cold and the water temperature is low, while in summer it is the opposite, high, and it may be unusable. The onsen itself overall looks and feels muddy, both in the water and on the bottom. You need to be careful about gases from the water, especially in calm weather. It is unclear how safe it is to stay there at all if there is no wind, and we were there on a windy day. And of course it is critical not to be alone. About the baths: 1. Onsen lake. Because of the jets of hot onsen water, the whole lake warms up, changes color, and becomes an onsen. The bottom is earthy and muddy, rough, with small stones. The water is cloudy gray with muddy sulfur mixtures and foam. The temperature near the edge of the lake was 21.6. 2. Small shallow oval bath. The bottom is earthy and muddy. The depth is very shallow, so you cannot immerse your whole body even close to fully. The water is cloudy white-gray, and the temperature was 22.3. 3. Blurred bath with a separate water source. The bottom is earthy and muddy. The depth is very shallow, so you cannot immerse your whole body even close to fully. The water is cloudy gray with muddy sulfur mixtures and foam. The temperature was 33.2. A very unusual place with an overwhelming natural atmosphere and an incredible onsen lake, but the baths themselves were too cool in early April, and the shallowness of the baths separate from the lake does not let you fully enjoy the water. 08.04.2026