The Gorges du Tarn (oc|Gòrjas de Tarn) is a canyon formed by the Tarn (river) between the Causse Méjean and the Causse de Sauveterre, in southern France. The canyon, mainly located in the Lozère département, and partially in the Aveyron département, is about 53km (33miles)-long (from the village of Quézac to Le Rozier, from to) and 400 m to 600 m deep.
The architecture of the gorges involves Mesozoic limestone plateaux downstream presenting sub-vertical cliffs. Faults like the Hauterive Fault explain the important water sources in the region of Sainte-Enimie (the Burle source and the Coussac source, the latter joining the Tarn in an impressive waterfall), and the more complex geology in the upstream part of the canyon.
In the Quaternary, the gorges were also affected by volcanic activity whose traces can be found in the Causse de Sauveterre, in the form of a double or anticlinal volcanic dip, and in the basaltic rocks next to Eglazines.
The climate is Mediterranean, with relatively mild winters and very warm summers.
Tourism is a main factor of development in the region, with activities that include:
Many castles have been built along the Gorges, most of them dating back to the Middle Ages, such as those of Castelbouc, Lacaze, Hauterives, La Malène or Saint-Rome-de-Dolan.