Castet is a commune in the Pyrénées-Atlantiques department in south-western France. It lies on the river Gave d'Ossau, in the Ossau Valley. The Lac de Castet is an artificial lake in Castet, created by a dam in the Gave d'Ossau.
Country: France
Region: Nouvelle-Aquitaine
Area: 23.53 km² (9.08 sq mi)
Elevation: 419–2,020 m (1,375–6,627 ft) · (avg. 493 m or 1,617 ft)