Along Route 299 in the township of Kanna stands a wall of mountain cliff known as the Sazanami-iwa (“ripple rock”). Discovered in 1953 during the construction of a road, it was initially believed to be just that—a rock with ancient ripple marks; but it later turned out to be something much more. Often referred to as the “ripple marks of Sebayashi” after the former village it is located in, the rock was thoroughly researched by Gunma University upon its discovery. When its team of academics made a report, it mentioned “strange…
