The largest river in Italy, rises 6000 ft. above sea-level in the Cottian Alps, and after 20 m. of rocky defiles emerges on the great Lombardy plain, which it crosses from W. to E., receiving the Ticino, Adda, Mincio, and Trebbia, tributaries, and enters the Adriatic by a rapidly growing delta. Its total course is 360 m.; the width and volume of its stream make it difficult to cross and so a protection to all Italy. The chief towns on its banks are Turin, Piacenza, and Cremona.