In the heart of Bandai-Asahi National Park, at an altitude of 800m/2,624ft, the 3.6km/2.2mi-long path of the "ponds of five colours" unveils an exceptional natural landscape made up of a series of ponds formed following the eruption of Mount Bandai in 1888. The acidic water of volcanic origins turns amazing colours from green to red and blue, depending on the seasons. Planted after the eruption, a magnificent forest of pine and cedar trees is home to a rich diversity of wildlife and plants. Not to be missed in autumn.