The waters of the pond in Hokkaido change color depending on the weather, however whether this is emerald green in spring, whitish blue in winter or bright azure during the rest of the time, the colors surprise with their brightness. In such shades, the pond is obliged to admix aluminum hydroxide in water. The pond itself has an artificial origin - it was created as a warning of erosion in this area in case of the eruption of the volcano Tokati.
