Lake Onneto

In eastern Hokkaido, Lake Onneto spreads quietly at the foot of Mount Meakan within Akan-Mashu National Park. Meaning "old pond" or "large pond" in the Ainu language, this lake lies on high ground at about 623 meters in elevation, and because its surface shifts moment by moment between emerald green and cobalt blue depending on the viewing angle, time of day, and weather, it is also known as "Goshiki-numa" (the five-colored pond). The stillness embraced by primeval forest, and the divine forms of Mount Meakan and Mount Akan-Fuji reflected on the water, make it a leading natural power spot of eastern Hokkaido.

Highlights

• A Surface That Turns Five Colors: A mystical surface that changes color with the weather and the angle of light, showing a different face on every visit.
• Views of Mount Meakan and Mount Akan-Fuji: The mountains rising beyond the lake and, on windless days, their inverted reflections on the water form a stunning view.
• The Primeval Forest Path: A walking route around the roughly 2.5-kilometer shoreline, a soothing space wrapped in untouched nature and stillness.
• Yu-no-Taki Falls: Nearby, "Onneto Yu-no-Taki," where a hot spring cascades as a waterfall, adds to the wealth of things to see.

Seasonal Enjoyment

From fresh green through summer, the blue of the lake stands out against the deep green for a refreshing walk. In autumn, foliage dyes the shoreline and, combined with the five-colored surface, creates a stunning scene. On clear mornings with fresh air, the surface mirrors the mountains for a perfect photo opportunity. In winter, part of the road may be closed, so check road conditions before visiting.

Access and Basic Information

• Location: Moashoro, Ashoro-cho, Ashoro-gun, Hokkaido
• Access: About 30 minutes by car from Lake Akan Onsen. In summer, buses also run from the Lake Akan shore. Public transport is limited, so a car is convenient.
• Visiting Hours: Daytime strolling is recommended (take care at night and in winter)
• Admission: Free
• Parking: Available

Practical Travel Notes

• Lake Data: A small lake at about 623 meters in elevation, roughly 2.5 kilometers around, with a maximum depth of about 9.8 meters. On clear mornings the surface is said to take on a clear blue.
• Onneto Yu-no-Taki: About 1.4 kilometers by walking path from the parking lot south of the lake. This roughly 30-meter waterfall is known for a rare phenomenon in which microorganisms produce manganese oxide, and it is designated a national natural monument.
• Winter Road Closures: In winter, part of the surrounding road may be closed. Check road conditions before visiting.
• Nearby Real Spots: About 30 minutes by car, Lake Akan Onsen is a hot-spring town on the shore of Lake Akan, known for marimo algae. Combining the two enriches an eastern Hokkaido trip.

A Quick Tip

Because public transport access is limited, visiting by car is realistic. The shoreline path is a natural trail, so comfortable shoes are recommended. Windless mornings, when the surface becomes a mirror, are the perfect time to catch an inverted Mount Akan-Fuji. Pairing the visit with nearby Onneto Yu-no-Taki lets you enjoy the great nature of eastern Hokkaido. In winter, always check road conditions before setting out.

📚 Sources

The information in this article is organized from the public information on Akan-Mashu National Park provided by the Ministry of the Environment, tourism details on Lake Onneto published by the town of Ashoro and the local tourism association, and on-site signboards. Information on the walking paths, road openings, and Onneto Yu-no-Taki can be checked through the operators' official information. Fees, hours, and access may change, so please always confirm with official sources before you set out.

Visitor Checklist

• Estimated time: About 30 minutes to an hour to enjoy the view from the shore, or roughly half a day to walk the paths.
• What to bring: As you walk through nature, prepare comfortable shoes, water, insect repellent, and cold-weather gear.
• Getting around: Public transport is limited, so visiting by car is realistic; in winter, always check road conditions before setting out.
• Suggested route: Enjoy the views of Mount Meakan and Mount Akan-Fuji from the shore, and if time allows, extend along the path toward Onneto Yu-no-Taki.
• A note on safety: Care is needed at night and in winter, so move during daylight hours, and aim for a windless morning with a still surface.