The Nagara River (長良川 Nagara-gawa) has its source in the city of Gujō, Gifu Prefecture, and its mouth in the city of Kuwana, Mie Prefecture, Japan. Along with the Kiso River and Ibi River, the Nagara River is one of the Kiso Three Rivers of the Nōbi Plain. Previously, the river was named Sunomata River (墨俣川 Sunomata-gawa). With a length of 166 km (103 mi), it drains an area of 1,985 square kilometres (766 sq mi) in the Chūbu region and empties into Ise Bay. The government of Japan classifies it as a Class 1 river.