Here is center of Japan at A.C.800. Name is "Hitachi So-ja-gu". Hitachi is old name of the Ibaraki prefecture. So-ja-gu means similar "the Central shrine pavilion"
This is the Slide. I found ancient it at junior school in Ishioka city. It shows us "オスナ" means "don't push", "ニコゝ" is onomatopoeia that means "Keep Smiling". Be friendly together!