[Oga Peninsula, Akita Prefecture] Strange rock formations on the west coast where ancient legends are passed down

Oga Peninsula's most famous tourist spots are Godzilla Rock and Daisankyo Pier , which are popular for their intriguing shapes, but these are also precious rock formations that allow us to witness the history of the Earth. Here, we will change our perspective a bit and focus on the rocks that make up the strangely shaped rock formations, in order to feel the breath of the Earth.

There are almost no sandy beaches on the western coastline of the Oga Peninsula. It is a rugged coastline known as a rocky coast or rocky shore. All of the rocks on the coast appear to have some kind of strange shape.

As depicted in the Oga Screen, there are almost no sandy beaches on the western coastline of the Oga Peninsula. Moreover, the rocks on the coast all appear to have some kind of strange shape

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17 strangely shaped rocks selected as one of Japan's 100 strangely shaped rocks

have been selected as part of the "100 Strange Rocks of Japan Plus" by the Japan's 100 Strange and Editorial Committee : " Shishiotoshi" , "Oni no Tawara Korogashi" (Demon's Bag Rolling) , " Oni (Demon's Hidden Path) , "Sakurajima "Osanbashi Pier" , and Butaijima" (Butai Island) on the west coast; "Gamera Rock", "Godzilla's Tail Rock", "Godzilla Rock", "Twin Rocks", "Hokakejima" (Futojima Island), "Green Tuff", "Candle Rock", "Tsubaki no Shiraiwa" (White Camellia Rock), "Oni no Sentaku Rock", "Azukiiwa" (Red Bean Rock), and "Oni no Kakurezato" (Demon's Hidden Village), the only one located in the mountains . 124 strange rocks have been selected for the " 100 Strange Rocks of Japan Plus " list, but Akita Prefecture ranks first in terms of the number of strange rocks, and the Oga Peninsula is the only place in Akita that has such a selection . The Oga Peninsula is truly the number one paradise of strange rock formations in Japan.

Here we introduce some of the most notable rock formations on the west coast. The Edo period travel writer Sugae Masumi also toured the area by boat, and must have been very impressed by the Osanbashi Pier, as he left behind detailed drawings of the rock formations.

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"Oni no Tawara Korogashi" at Nyudozaki, a representative tourist spot on the Oga Peninsula

"Oni no Tawara Korogashi" is a strangely shaped rock formation at Cape Nagakute, a little south of Nyudozaki along the coast. A brownish path stretches out towards the sea through the middle of the pink rock formation. It looks exactly like the traces left by an ogre rolling a rice bale.

granite, formed about 90 million years ago when magma slowly cooled and solidified deep underground , making it the oldest rock found on the Oga Peninsula. The dark rock above the pink rock is volcanic breccia, formed about 70 million years ago when magma cooled rapidly and broke down into small, sharp, angular rocks that then rejoined to form larger chunks. The brown rock path basalt , formed about 21 million years ago when erupted magma cooled.

At Oni no Tawara Korogashi, you can witness the rare sight of rocks from three different eras, when the Japanese archipelago was still part of the Eurasian continent, all in one place

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The rocks of Nyudozaki's "Shikaotoshi" used in stone-grilled dishes

Shika Otoshi is a sheer rocky cliff on the east side of Nyudozaki Coast. 90 million year old granite , volcanic breccia, and welded tuff . These rocks have a dense structure and are hard, so they are used in Oga's specialty, stone-grilled cuisine

It is said that the name "Shikaotoshi" comes from the fact that Oga was once home to a large number of deer, and the deer that had multiplied so much were pushed off the cliff

＜Oni no Tawara Korogashi (Rolling the Demon's Straw Bag) and Shika Otoshi (Deer Dropping)＞INFORMATION

• Facility name: Nyudozaki
• Location: Nyudozaki, Kitaura, Oga City, Akita Prefecture
• Phone number: 0185-24-2100 (Oga City Tourism Association)
• URL: Nyudozaki
• access:
• Train: Approximately 30 minutes by Namahage Shuttle from Oga Station on the JR Oga Line
• By car: Approximately 45 minutes from Showa Oga Peninsula IC on the Akita Expressway

GOOGLE MAP

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Osanbashi Pier: A stone bridge created by the power of nature

In the southern west coast of the Oga Peninsula, in the area known as the West Coast Area, there are well-known strange rock formations called "Osanbashi Pier" and "Butaijima Island."

Osanbashi Pier is a stone bridge whose center has become passable due to erosion caused by waves over many years. It's 10 meters high, allowing tourist boats to pass under. While it's now connected to land, records show that it was underwater in the early Edo period (Oga Folding Screen, designated a cultural property by Akita Prefecture). Masumi Sugae, an Edo period traveler who left behind a the "Five Winds of Oga" (Oga's Autumn Winds, Oga's Spring Winds, Oga's Bell Winds, Oga's Island Winds, included an illustration of Osanbashi Pier (known as "Osanbashi" in his book) in his book Osanbashi Pier.

Osanbashi Pier are the Monzen Formation, a hardened basaltic scoria that erupted from a volcano 29 to 36 million years ago. Because the rock itself is brittle, it is thought to have been carved out by the erosion of waves. Scoria is formed when magma cools rapidly as it rises, causing the volatile components (mainly water) it contains to vaporize all at once, resulting in porous rock fragments containing numerous air bubbles that are erupted. It is the same as pumice, but pumice is often andesite-based and is white in color, while basaltic scoria is darker in color.

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Butai Island is a sky stage where legend has it that a dance was performed to welcome Emperor Wu of Han

Butaijima is not an island, but a huge rock that rises like a stage towards the sea on a cliff that is connected to the mainland, standing 60m above sea level. The top is flat, and "long ago, when Emperor Wu of Han descended on this land, a shrine maiden danced on it ," and it was already known as Butaijima during the Edo period. When you view Butaijima from a sightseeing boat, it truly looks like a "stage floating in the sky."

Butaijima is made of the same basalt scoria , and is said to have originally been underwater, before rising and becoming connected to the mainland. When the rock was first underwater, its head protruded above the water like an island. It was then eroded by the waves, becoming flat, before rising and settling into its current shape. It took Butaijima 36 million years to take on its current shape. Here lies proof that the Earth is alive.

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A sightseeing boat that lets you enjoy the strange rock formations of the west coast from the sea

To see the strange rock formations on the west coast, take the Oga Peninsula sightseeing boat west coast cruise from Monzen Fishing Port, where you can enjoy spectacular views from the sea. You can also see the famous "Godzilla Rock," which is definitely recommended.

<Osanbashi Pier and Butaijima> INFORMATION

• Facility name: Oga Peninsula Sightseeing Cruise
• Location: Haraigawa River, in front of the main temple gate, Funakawa Port, Oga City, Akita Prefecture
• Phone number: 0185-38-2050
• Price: West Coast Cruise Adults 2,500 yen, Children 1,250 yen
• Operating period: Please inquire (closed during winter)
• URL: Oga sightseeing cruise ship
• access:
• Train: Approximately 30 minutes by taxi from Oga Station on the JR Oga Line. Rental cars available near Oga Station
• By car: Approximately 70 minutes from Showa Oga Peninsula IC on the Akita Expressway

GOOGLE MAP

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What did you think of our introduction to the strange rock formations on the west coast? The formations created by the earth are both artistic and fascinating. In addition to the west coast, the Oga Peninsula is home to many other strange rock formations and viewpoints, such as Cape Shiosezaki, home to the "Godzilla Rock" at the southern tip, Unosaki Coast on the south coast, known as "Akita's Uyuni Salt Flats," and Cape Tateyamazaki, geologically important for its "Green Tuff." There are also hot springs in the Nyudozaki area, as well as the Namahage Museum and Oga Mayama Folklore Museum, where you can see Namahage, and the delicious "heated stone cuisine," making for a truly fascinating experience. Why not take a leisurely trip?

We have introduced spots on the south coast in a separate section, so please refer to that as well