The highest point in the Massif Central, the Sancy stratovolcano (6,184 ft / 1,885 m), is part of the Monts Dore massif that extends southwest of the Puy-de-Dôme department. It was shaped 250,000 years ago, at the end of the volcanic activity of this area initiated about ten million years ago. It consisted of vast basalt effusions interrupted by phases of sleep of several hundred thousand years. The sharp reliefs of Puy de Sancy bear witness to its relative youth and the major geological changes it has undergone.