Oyu Stone Circles

Each of the two stone circles is formed with a smaller ring inside the larger one, both constructed by arranging stones collected from the nearby river five to six kilometers away. Each circle contains elongated stones standing straight up with surrounding smaller stones in a radiating pattern forming a sundial which points toward the sunset on the summer solstice. They are representative stone circles from the Jomon Period constructed in consideration of their positioning, which suggests that the Jomon people were aware of the sun's movement. Their construction would have required a great deal of labor and a strong spirit, and hence these structures are highly important in learning about the spiritual culture structure of the time. Several artifacts related to festivals and items used for worship have been also discovered, which provide material evidence of the advanced spiritual culture and social structure of the Jomon Period.