The Zaña River is a small river in northern Peru. The river is 119 kilometres in length and begins in the Andes of Cajamarca Region and ends at the Pacific Ocean in Lambayeque Region. In the lower part of the river valley, where the river flows through the coastal desert of Peru, the cultivation of irrigated crops is extensive and the Zaña is usually dry near its mouth. Upriver, at higher elevations in the Andes, precipitation is much greater and downstream floods are common. One such flood wiped out the important city of Zaña in 1720. Zaña has been rebuilt, but has never regained its former prominence as an urban center. Other towns in the lower valley are Mocupe, Cayalti, Nueva Arica, and Oyotun.