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A Giant Wheel Stone of Global Rarity! What is the "Kurumaishi" at Cape Hanasaki, Nemuro?
All around the world, you can find various formations that seem as if they were meticulously designed by someone, yet were created entirely by nature. Did you know that you can see one such natural marvel right here in Hokkaido? It's the peculiar "Kurumaishi" rock at Cape Hanasaki in Nemuro City. As its name suggests, it's a large rock shaped just like a car tire. How on earth was it formed?
To see the Kurumaishi, you'll walk along a promenade from the Cape Hanasaki parking lot. The surrounding area is maintained as a park, so you can take a leisurely stroll while enjoying the natural scenery. In the distance, you'll spot the Hanasaki Lighthouse. It has been selected as one of the "50 Lighthouses of Japan" and stands about 10 meters tall.
As you pass the lighthouse and get closer to the coast, the Kurumaishi will come into view. Cape Hanasaki, where the Kurumaishi is located, is a sea cliff jutting out into the Pacific Ocean. There, a massive wheel-like rock, about 6 meters in diameter, emerges from the cliff face.
The pattern, known as radial columnar jointing, features numerous columnar cracks spreading out in a radial pattern, making it look almost artificially designed. It's hard to believe that this was formed naturally. However, if you look at the rocks along the coast, you'll notice they are all angular. The sharp-witted might guess that these are the raw form of the Kurumaishi.
The angular rocks on the coast are dolerite (coarse-grained basalt), formed when magma cooled and solidified underground. The dolerite in this area is said to have been formed about 60 million years ago during the Cretaceous period. It is believed that after the hot, molten lava was rapidly cooled, seawater seeped into the still-molten interior, causing further rapid cooling and creating the Kurumaishi. A Kurumaishi of this size is rare worldwide, and it was designated as a National Natural Monument in 1939.
While the largest 6-meter-diameter Kurumaishi captures most of the attention, a closer look reveals several other Kurumaishi ranging from 1 to 2 meters in size. It's a slightly strange feeling to be able to see a sight today that was born an unimaginably long time ago, 60 million years in the past.
As mentioned earlier, the area is maintained as a park, so visiting during the snowy season to see the Hanasaki Lighthouse and the landscape is also a wonderful experience. Just be careful when walking along the coast, as it can be slippery.
＜Special Thanks＞
Nemuro Tourism Association
Location: Tourist Information Center, 2-10 Kowa-cho, Nemuro, Hokkaido
Phone: 0153-24-3104
Official Website: https://www.nemuro-kankou.com
To see the Kurumaishi, you'll walk along a promenade from the Cape Hanasaki parking lot. The surrounding area is maintained as a park, so you can take a leisurely stroll while enjoying the natural scenery. In the distance, you'll spot the Hanasaki Lighthouse. It has been selected as one of the "50 Lighthouses of Japan" and stands about 10 meters tall.
As you pass the lighthouse and get closer to the coast, the Kurumaishi will come into view. Cape Hanasaki, where the Kurumaishi is located, is a sea cliff jutting out into the Pacific Ocean. There, a massive wheel-like rock, about 6 meters in diameter, emerges from the cliff face.
The pattern, known as radial columnar jointing, features numerous columnar cracks spreading out in a radial pattern, making it look almost artificially designed. It's hard to believe that this was formed naturally. However, if you look at the rocks along the coast, you'll notice they are all angular. The sharp-witted might guess that these are the raw form of the Kurumaishi.
(Photo courtesy of Nemuro Tourism Association)
The angular rocks on the coast are dolerite (coarse-grained basalt), formed when magma cooled and solidified underground. The dolerite in this area is said to have been formed about 60 million years ago during the Cretaceous period. It is believed that after the hot, molten lava was rapidly cooled, seawater seeped into the still-molten interior, causing further rapid cooling and creating the Kurumaishi. A Kurumaishi of this size is rare worldwide, and it was designated as a National Natural Monument in 1939.
(Photo courtesy of Nemuro Tourism Association)
While the largest 6-meter-diameter Kurumaishi captures most of the attention, a closer look reveals several other Kurumaishi ranging from 1 to 2 meters in size. It's a slightly strange feeling to be able to see a sight today that was born an unimaginably long time ago, 60 million years in the past.
As mentioned earlier, the area is maintained as a park, so visiting during the snowy season to see the Hanasaki Lighthouse and the landscape is also a wonderful experience. Just be careful when walking along the coast, as it can be slippery.
＜Special Thanks＞
Nemuro Tourism Association
Location: Tourist Information Center, 2-10 Kowa-cho, Nemuro, Hokkaido
Phone: 0153-24-3104
Official Website: https://www.nemuro-kankou.com
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Team Buchineko
We are "Team Buchineko," with many connections to tourist spots and facilities in Hokkaido. Even things that seem ordinary to us living in Hokkaido are wonderful resources. We will continue to share the charm of this amazing prefecture.
