The Gave de Pau is a river of south-western France. It takes its name from the city Pau, through which it flows. The river is 183 kilometres (114 mi) long, and its source is at the Cirque de Gavarnie in the Pyrenees mountains. The Gave de Pau joins the Gave d'Oloron in Peyrehorade to form the about 10-kilometre (6 mi) long Gaves réunis (united Gaves), which is a left tributary of the Adour. The Gaves réunis is often considered to be part of the Gave de Pau.