Apennines (Ital. Appennini, Lat. Mons Apen-ninus), a mountain-chain extending 740 miles uninterruptedly throughout the whole length of the Italian peninsula. It belongs to the system of the Alps. The average height of the entire chain is about 4000 feet, which in the north sinks to 3500 feet, and in the Abruzzi rises to 7000 feet. Here, in Monte Corno, the highest peak of the range known as Gran Sasso d'ltalia, they reach an elevation of 9574 feet, and in Monte Velino, of 7916 feet. The Apennines are crossed by thirteen principal passes; and seven of these are traversed by railways. The principal chain exhibits, for the most part, a dreary and barren appearance. It looks like a vast wall, with very few projecting peaks to break its dull monotony. Only in the Abruzzi, and above all, in the marble mountains of Carrara and Seravezza, do the bold and magnificent forms of the Alps appear. Where water is plentiful there is no lack of rich pastures and dense forests; but usually only thin grass and wild scrubby bushes cover the stony slopes. The greater number of the forest brooks, with deep rocky ravines, during summer are dry.

Where the mountains dip down to the sea, as at the Riviera of Genoa and the Gulf of Naples, a rich, peculiarly southern vegetation clothes the declivities. There is no region of perpetual snow; but the summits of the Abruzzi and the lofty peaks of Lunigiana are often covered with snow from October far into May.