Nagatoro Iwadatami

The Iwadatami of Nagatoro is a tourist spot that boasts Nagatoro's designation as a scenic spot and natural monument by the country in 1924. The topography of Nagatoro is quite unique even in Japan, and is also known as the "Window of the Earth". It's possible to actually walk on the Iwadatami that continues along the Arakawa River, allowing you to get up close and personal with this unique terrain. Another recommended way to spend your time is to sit on the rocks and feel the nature of Nagatoro at a leisurely pace.

The Nagatoro Iwadatami consists mainly of crystalline schist that was formed when plates were dragged down to a depth of about 20 to 30 kilometers underground, approximately 66 to 85 million years ago. The unique feature of Nagatoro is the eroded rock walls called "Akabeki," which were formed by the strong flow of the Arakawa River and are registered as natural monuments. They are one of the highlights of Nagatoro's rare geological formations, allowing visitors to experience the mysteries of nature.

The best time to visit Nagatoro's rock formations is during the beautiful autumn foliage season! The natural surroundings of the rock formations along the Arakawa River turn red, creating a stunning view that attracts many tourists from within Kanto prefecture. In particular, the combination of the bright red foliage and the beautiful rock formations seen while rafting down the river is a breathtaking experience that cannot be missed during a visit to Nagatoro in the fall.

Saitama Prefecture is famous for being a landlocked prefecture, but approximately 17 million years ago, there was also a sea in Saitama Prefecture. Long ago, the sea spread around Chichibu in Saitama Prefecture, and remnants of it can be seen in the rocky pavement of Nagatoro. It is said that the megalodon, which exceeded a total length of about 13 meters, lived there, and many shark fossils have been found in the surrounding area of Nagatoro. Since many fossils can be found in the Nagatoro area, you might be able to discover fossils on the rocky pavement.

In Nagatoro's rock bed, there are mysterious deep holes called "pot holes" that nature created over a long period of time. When the rocks were at the bottom of the river, they were eroded by pebbles swirling in the water, allowing you to feel the greatness of nature.