The strata around the Cape Inubosaki, where the Inubosaki Lighthouse is located, were formed as long ago as 120 million years ago during the Cretaceous Period when dinosaurs flourished. The Cretaceous era strata can be seen here because the uplift lifted the old bedrock deep underground, while the Kanto Plain to the west has strata of a newer age. Only the Cape Inubosaki juts out into the Pacific Ocean because its old, hard bedrock has been able to withstand erosion.
