A cursory glance at a map of Italy reveals important geographical features that profoundly influenced the boot-shaped peninsula’s history. The most striking aspect is the mountainous and hilly terrain. To the north, the Alps—cited by the poet Dante as being the natural border of Italy—crown the peninsula and form Italy’s boundaries with France, Switzerland, Austria, and Slovenia. Pockmarked by more than a thousand glaciers and with peaks over 13,000 feet in height, the Alps give a picture of rugged beauty. The most famous peaks include Monte Blanco (15,771 feet), Monte Rosa (15,203 feet), and the Matterhorn (14,692 feet). The Alps affect the country’s climate by serving as a barrier to winds coming from the north and west and have been an important factor in the area’s military history. In modern times, the starkly beautiful terrain accounts for the importance of the area’s skiing and tourist industries. Besides the Alps, a long mountain range runs down the entire length of the peninsula into Sicily, the island at the toe of the Italian boot. With their highest peak at 9,560 feet, the Apennines are lower than the Alps but are 745 miles long and extend practically to the sea. A recent geological formation, the Italian Peninsula is subject to earthquakes, and a great deal of volcanic activity still exists. The country includes Europe’s three active volcanoes ( Vesuvius, Etna, and Stromboli), and various forms of volcanic action are visible in areas such as the Campi Flegrei and Pozzuoli, outside Naples, and islands such as Ischia in the Bay of Naples. Depending on location, these volcanic phenomena produce thermal springs—a source of revenue because of their supposed therapeutic effects—gas emissions, and unpleasantly abrupt alterations in ground levels.
Mountains and hilly areas represent 77 percent of the peninsula’s territory, while plains make up 23 percent. Arable land is thus strictly limited, which has contributed to a high population density in the cities and towns and to vast emigration. The peninsula has also had an abundance of unhealthful marshlands, especially in the Veneto, Tuscany, and Lazio. Drained relatively recently, they were hotbeds of malaria and other diseases and hampered the peninsula’s economic development. Fertile plains are practically restricted to the Po River Valley in the North, while small fertile areas exist around Naples, Catania, and other areas. The climate, which is cool and wet in the North and hot and dry