Final answer:
The Apennines is the mountain range that runs along the middle of the Italian peninsula, unique to Italy and a defining feature of the Alpine region.
Step-by-step explanation:
The mountain range that runs up and down the middle of the Italian peninsula is the Apennines. These mountains, also part of the broader Alpine region, are central to Italy's geography.
The Apennines run the length of Italy and have played a significant role in the country's history, including acting as a divider among cultural groups and influencing the preservation of ancient Roman roads.
Unlike the Alps, which are located in multiple European countries including France and Slovenia, or the Andes, which run along South America's west coast, the Apennines are exclusively found in Italy.