In Central Massif's south, in the Lozere department, the « Causses » shape a very particular great natural country. A land « near the stars », high from 800 to 1200 m.
The Causses are shaped in secondary era. In this old times, sea has invaded the whole country. Down hot climate, sea animals' shells based limy sediments accumulate and harden. Later, further to the climate change, with the high mountains rise, limestone plate breaks, shaping valleys and deep gorges : these of Tarn, Jonte, Lot and Dourbie. These valleys delimit distinct and well separate causses : Sauveterre(safe-earth), Méjean and Noir(black).
The causse is an bare and stony country, broken with some forests. One of this Wild Country's essential charms lies in existing contrast between aridity of plateaus and coolness of valleys.