Kitashiobara Village, Yama County, Fukushima Prefecture. About a 20-minute walk from the Urabandai Site Station along the 'Renge-Nakase Pond Trail'. The scenery visible from the observation deck within the trail is Nakase Pond.
While Goshikinuma is famous for its "various blue lakes and marshes," Nakase-numa is quiet. It is a suitable path for leisurely strolling while conversing with oneself, basking in the light filtering through the trees. The sounds you hear are the voices of wild birds and the occasional sound of water.
A small hill appears to float in the marsh──.
From the observation deck on the path, looking down at the marsh, hills are scattered across the green surface of the water, resembling islands. Trees grow, moss thrives, and they look as if they have been there for hundreds of years. However, this landscape was not like this until just over 100 years ago.
Why are the hills in the marsh there?
These hills are referred to as "nagareyama" in geology.
On the morning of July 15, 1888 (Meiji 21), Kobandai, located on the northern side of Mount Bandai, suddenly collapsed. It was a landslide. The fallen rocks and debris flowed downwards at speeds exceeding 100 km/h. This is called "rock avalanche".
The flowing rock avalanche blocked rivers, filled valleys, engulfed Hibara Village, and created about 300 lakes and marshes.
And──among the large boulders carried by the rock avalanche, some of a certain size were not completely shattered in the flow and were transported as chunks, remaining as "hills" where they stopped.
That is the nagareyama.
The hills that appear to float in Nakase-numa are all boulders that were transported in one go on the morning of July 15, 1888. The parts that rise above the water surface appear as hills, but below the water, there are even larger bodies resting.
Geosite certified by the Bandai Geopark
The area of the Urabandai Goshikinuma Lake Marsh Group, which includes Nakase-numa, is a geosite certified by the Bandai Geopark. It is known as one of the few places in Japan where you can observe "landforms created by volcanoes in real time."
Normally, landslides and rock avalanches are geological events that occur on a scale of tens of thousands to hundreds of thousands of years. Their "traces" are only deciphered by experts through boring surveys.
However, the nagareyama of Nakase-numa has traces of an event that occurred just 137 years ago, right in front of our eyes. Without reading specialized books, one can visually understand, "Ah, that hill is the rock that flowed here." Such a friendly geological heritage is rare even globally.
Walking after knowing, Nakase-numa
Walking along the Nakase-numa exploration path without knowing anything is a peaceful nature stroll. The fresh green mirror, the chirping of birds, and the occasional sound of water.
However, when you walk knowing that 'the hill in the middle of that swamp is a rock mass that flew in on July 15, 1888,' the scenery becomes completely different.
When we guide visitors at Nakase-numa, the moment we arrive at the observation deck, we tell them, 'That is Nagareyama.' The usual response is, 'Huh, what does that mean?' From there, for 20 minutes, while discussing the rock debris avalanche and Mount Bandai, when we look down at the swamp again, the expressions on our guests' faces change completely.
The surface of the swamp becomes more than just a surface of water. The hill becomes more than just a hill. This is a place where the time of the Earth and the time of humans intersect at your feet—there is a moment when you truly feel this.
If you visit Nakase-numa
Nakase-numa is located in Kitashiobara Village, Yama County, Fukushima Prefecture. It takes about 20 minutes from the Urabandai Site Station parking lot via the exploration path. The path is relatively flat, but there is a slope for a section leading to the observation deck. It is a course that is easy to walk even for those who are not very confident in their physical strength.
The season of fresh greenery (May to June) is the most beautiful
The biggest highlight of Nakase-numa is the view of Mount Bandai and Nagareyama from the observation deck. Right in front is the explosive crater of Mount Bandai. Below it spreads the scenery of Nakase-numa. You can encounter beautiful landscapes throughout the four seasons.
Places to visit together
- Goshikinuma Nature Exploration Path — A 'path where you can see various blues' created by the same rock debris avalanche. Combine it with Nakase-numa for a leisurely visit.
- Lake Hibara — The largest lake in Urabandai, created by a rock debris avalanche blocking a river. Beneath the lake lies the village of Hibara.
- Bandai Mountain Geopark — Learn about the landforms created by volcanic eruptions from a geological perspective.
Would you like to join us on a journey to encounter stories?
At Tabinoito, guide Catherine, who has lived in Urabandai and Aizu for half a century, shares stories of the land that are not found in guidebooks, providing guidance limited to one group per day.
The 'Half-Day Course of Geology and History' that visits the three points of Nakase-numa's Nagareyama, Goshikinuma's blue swamp, and the submerged village of Lake Hibara can also be arranged upon consultation. You can leave all long-distance driving and arrangements to us.
If you want to "walk slowly in nature" or "take a stroll as a couple"—feel free to let us know any requests. Just a consultation is fine, and we will not pressure you with persistent sales.
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👉 View travel plans for senior couples:
https://tabinoito.com/senior/
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Related articles:
The village submerged at the bottom of the lake ── Memories of Hibara Village erased by the 1888 eruption of Mount Bandai
Reference materials
- Bandai Mountain Geopark - Goshikinuma Lake Area
- 1888 Eruption of Mount Bandai (Wikipedia)
- Bandai-Asahi National Park (Ministry of the Environment)
- Urabandai Visitor Center on-site exhibition and interviews
- On-site coverage (visit and interviews by Tabinoito guide, Catherine)
Author of this article
Catherine ── A guide who has lived in Fukushima Prefecture, Urabandai, and Aizu for half a century. Founder of the private tour company "Tabinoito". Deeply knowledgeable about local nature, history, and cultural beliefs. Providing guided tours of Urabandai and Aizu while sharing stories of the land that are not found in guidebooks, limited to one group per day.
