Massif Central, large upland area, south central France, covering about one-sixth of the area of France. It reaches a high point of 1,886 m (6,188 ft) atop Puy de Sancy. Major sections include the Auvergne, in the center, a region of ancient lava flows and eroded volcanic necks (puys); the Causses, in the southwest, underlain mainly by limestone; the rugged Cévennes, in the southeast, overlooking the Rhône-Saône Valley and the Midi section of southern France; and a series of low, rolling plateaus in Limousin, in the northwest. Saint-Étienne, Clermont-Ferrand, and Limoges are major industrial centers.