The Grands Causses Regional Nature Park consists of four major landscape entities determined by the geological base, land use, and relief. The weaknesses and strengths of these territories have been channeled by men over time to create the landscapes of the nature park. The Causses du Larzac, Causse Noir, and Causse de Sauveterre are stone landscapes perched around 2,788 ft (850 m) above sea level and made up of layers of limestone sediments dating from the Jurassic period. The causses fractured with the thrust of the Alps and the Pyrenees and the water dug deep canyons with imposing cliffs like the Gorges du Tarn.