The land on which the stone circle would come to be constructed was originally on a slight gradient. The Jomon people first leveled off the higher end of the slope (1) and used the soil to fill the lower end (2). Afterwards, they carried stones from the river and arranged them to form the stone circle (3).
The stones formed a three-dimensional structure due to the stone circle being built on land of differing elevations resulting from the partial leveling off and filling work. Construction of the stone circle took place over a long period of time.
