Italy's longest river at 405 miles, it passes through Piedmont and Lombardy before entering the Adriatic 30 miles south of Venice. It flows through Turin and Cremona, and it passes near Milan, Padua, Pavia, and Mantua. The river has a long history of floods, and the man-made levees called argini which protect towns and crops can exacerbate the floods. Pollution, especially from Milan, is becoming a major environmental concern.