In 1861 at Oshoro, southwestern Hokkaido, a party of herring fishermen, migrants from Honshu, were laying the foundation for a fishing port when they saw taking shape beneath their shovels a mysterious spectacle — a broad circular arrangement of large rocks, strikingly symmetrical, evidently man-made. What could it be? An Ainu fortress?
They would have been astonished to learn, as in fact they never did, that the Oshoro Stone Circle is a relic from a time before even war — let alone fortresses — likely existed in Japan.
Oshoro today is part of the city of Otaru, on its western fringe, 20 km from the city center and 60 km west of Sapporo.