Blue Pond

The Blue Pond (Aoiike) in the town of Biei is a man-made reservoir whose surface glows an ethereal cobalt blue. The mesmerising colour occurs when aluminium-rich water from nearby Shirogane Onsen mixes with the Biei River, creating colloidal particles that scatter sunlight. Dead larch trunks protruding from the luminous water create an otherworldly scene that has captivated photographers worldwide.

The pond gained international fame when Apple selected it as a default macOS wallpaper. In winter, spectacular illumination events transform the snow-covered pond into a magical light show.