Among the Massif Central, two areas are well known for their volcanic activity and their rich prehistoric heritage: The Grande Limagne, at foothill of The Chaîne des Puys, where vulcanism interfered with human settlements, and the Velay with its huge basaltic fissural eruptions and its numerous phreatomagmatic features which determine specific landscapes. In the Grande Limagne, Late Glacial and Holocene volcanic activity of the Chaîne des Puys had a severe impact on the plain evolution. Archaeological investigations demonstrate that a few Magdalenian and Mesolithic sites were directly affected by tephra falls. In Velay, fissuration and columnar jointing of basaltic lava flows played an active morphologic role during alteration and erosion. ...