About a third of the Italian territory is occupied by mountains, the main ones being the Alps and the Apennines. The internal side of the Alps is Italian, which stretches from west to east for about 1300 mk and is composed of two main sections, the western one, up to Lake Maggiore, is narrower and with the highest peaks, (Mont Blanc, according to summit e’Europa after Elbrus, and Monte Rosa) the eastern one is wider and its peaks are less high. The Dolomites rise up on the border between Veneto, Trentino-Alto Adige and Friuli-Venezia Giulia. At the foot of the eastern section of the Alps there are lower peaks, the Lombard Pre-Alps, the Venetian, Carnic, Julian and Karst ones. The Apennines wind for about 1300 km from north west to south, the Gran Sasso is the highest peak about 2914 m. they are composed of a main chain and other minor ones, such as the Tyrrhenian anti-Apennines and the Pre-Apennines on the Adriatic side. The main chain has a sinuous course, Liguria is very close to the sea then down it moves to the center of the peninsula, starting from Basilicata in Calabria it is divided into various reliefs and isolated massifs. In the Strait of Messina, the chain lowers to below sea level and re-emerges along the northern coast of Sicily, where it forms the Peloritani and Madonie mountains. The most ancient reliefs are found in Sardinia, the main ones are the Gennargentu and the Supramonte. The parameter of 600-700 meters is used in geography, in Italy, as a limit level to divide the mountain areas from the hilly ones. This “limit” altitude can change in other parts of the world, much depends on latitude, climate and other factors. In general, however, it is a very common parameter. moreover, the mountains of Italy are divided into two great chains: the chain of the Alps and that of the Apennines. These chains form a single large system, with a shape that resembles an “S”. The two chains, which have a different geological history, meet near Liguria, in particular at the Colle di Cadibona. They occupy all the Italian regions, up to Sicily. A separate discussion for Sardinia, where the mountains of the Sardinian-Corsican system are located, which do not belong to the Alps or to the Apennines.It is in the Alpine chain that the highest peaks in Italy are concentrated, all abundantly above the four thousand meters above sea level, some touching five thousand meters above sea level.