The Nubinai River (ヌビナイ川) is a wild, pristine waterway flowing from high up in the eastern reaches of the Hidaka mountains. With a good water level, it is easily one of Hokkaido’s most picturesque rivers, with some enjoyable and sometimes technical whitewater rapids. Most of this section of the river is flanked by high cliffs, adding to a feeling of wilderness. The entire riverbed is made up of almost perfectly spherical mini-boulders, which are nothing short of spectacular when seen through the river’s crystal clear water. This section suffers from a lack of water in the summer season, so it’s best run in spring or after heavy rain in the autumn.