Exposed to an altered oceanic climate, it is drained by the Garonne, the Arrats and various other small rivers. The commune has a remarkable natural heritage: a Natura 2000 site (“Garonne, Ariège, Hers, Salat, Pique et Neste”), a protected area (the “course of the Garonne, of the Aveyron, Viaur and Tarn) and four Natural zone of ecological, fauna and flora interest|natural zones of ecological, fauna and flora interest.
History
Made up of three ancient parishes (Saint-Martin de Christinag, Saint-Jean de Castel and Saint-Loup forming a priory), the parish of Saint-Loup depended on the jurisdiction of Auvillar.
Note also the ephemeral parish of Saint-Michel-de-Lastours and its bastide built near an artificial mound on the Agre plateau.
It was united during the Revolution with half of the parish of Saint-Martial en Condomois to form the commune of Bouque-de-Rax, the Arrats river flowing into the Garonne in the commune.