Three million years ago, tectonic plate movement began pushing on the Japanese archipelago from the east and west. The whole of eastern Japan was uplifted and the Ōu Mountains and Dewa Mountains began to form, like wrinkles appearing on the Earth’s crust. The force was so strong that strata were pushed and bent, creating folds.

Here you can see a “”recumbent fold”” which is about 20 m wide and 50 m tall, and looks like a folded futon. Because of its appearance, it has also been called a “”zigzag fold”” or “”accordion fold.””
This magnificent feature has been selected by the Geological Society of Japan as one of the 100 best geological structures of Japan.
There are many theories as to how exactly this fold formed, but the truth is still a mystery. It is interesting to think about how the fold formed while reflecting on the amazing power of the Earth.