The southeastern part of France is characterized by rugged terrain. The medium-altitude mountains located here rise to between 500 and 1700 m. Some of them, such as the Vosges and the Massif Central, are ancient Hercynian massifs that were subjected to tectonic displacements during the rise of the Alpine ridges. They are piles of stone blocks, cut by valleys with steep slopes.
In the central massif there are many extinct volcanoes, such as Cantal and Puy-de-Dome. Other less extensive ancient massifs are more impressive, such as the Maure and Estrell, although they do not exceed 900m in height. The Jura Massif are young mountains formed during the Tertiary period. These folded mountains of sedimentary origin, whose rock is dominated by limestone, have a sharper relief. The ridges have narrow valleys and gorges through which transport routes run. The same reliefs of the medium-altitude mountains are also found in the northern and southern foothills of the Alps, where the altitudes sometimes reach 2,000 m.