Which is the second largest region of Italy?

Piedmont is a region in northwest Italy which has an area of 25,402 km2 (9,808 sq mi) making it the second largest region of Italy after Sicily and a population of 4,269,714 as of 31 January 2021. The capital of Piedmont is Turin.

Piedmont is surrounded on three sides by the Alps, including Monviso, where the Po rises, and Monte Rosa. It borders with France (Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur), Switzerland (Ticino and Valais) and the Italian regions of Lombardy, Liguria, Aosta Valley and for a very small part with Emilia Romagna. The geography of Piedmont is 43.3% mountainous, along with extensive areas of hills (30.3%) and plains (26.4%).

The Alpine arc of Piedmont plays a vital part in the power production of the region and of northern Italy as a whole; the region’s hydroelectric plants supply energy for industry, transportation, and domestic use

Piedmont forms part of the great industrial triangle of northern Italy (Turin-Genoa-Milan), and its manufactures are widely diversified. Turin—the capital, largest city, and leading industrial centre—is the site of one of the largest automobile plants in Europe, as well as of printing, textile, and machine industries.