The Gimone is a 136 km long river in south-western France, left tributary of the Garonne. Its source is in the foothills of the Pyrenees, near Lannemezan. It flows north through the following départements and towns: Hautes-Pyrénées Gers: Saramon, Gimont Tarn-et-Garonne: Beaumont-de-LomagneThe Gimone flows into the Garonne near Castelsarrasin.