Sandwiched between the Monts d’Aubrac and the Margeride to the north, the Monts du Lévezoux and Lacaune to the west and the Cévennes to the west and southeast, the Grands Causses form arid high plateaus with altitudes ranging from 560 to 1247 meters. They are criss-crossed by rivers that have formed impressive gorges delimiting their borders.
The Causses were formed during the Secondary Era, when the area they now occupy was covered by a vast sea. When the sea retreated 70 million years later, it left behind deposits and sediments, limestone and marl, and numerous shell fossils. In the Tertiary era, the limestone table was lifted by the folding of the Alps, and tectonic plate movements split the plateau with a large number of faults, forming the basis of their present-day relief.
