Yamauchi Basin

Agricultural heart of Fukue Island in the Goto archipelago, a broad flat plain of rectangular rice fields flanked by Mount Nanatsudake and Mount Tetegadake to the west. The fertile soil here formed over tens of thousands of years: a volcanic eruption around 741,000 years ago dammed an ancient river, creating a lake where ash and sediment gradually accumulated. The surrounding hornfels mountains don't erode easily, so rainfall runs off cleanly into the rivers below, keeping the farming conditions consistently productive. The wide, open fields give a clear sense of just how much geology determines what a landscape can become.