The Arrats is a 162 km long river in southern France, left tributary of the Garonne. Its source is in the northern foothills of the Pyrenees, near Sariac-Magnoac. It flows north through the following départements and towns: Hautes-Pyrénées Gers: Castelnau-Barbarens, Aubiet, Mauvezin, Saint-Clar Tarn-et-Garonne: Saint-Loup It flows into the Garonne near Valence, between Castelsarrasin and Agen. References Rivers of France Rivers of Gers Rivers of Tarn-et-Garonne Rivers of Hautes-Pyrénées Rivers of Occitania (administrative region)