The Po is a river that flows either 652 km (405 mi) or 682 km (424 mi) – considering the length of the Maira, a right bank tributary – eastward across northern Italy, from a spring seeping from a stony hillside at Pian del Re, a flat place at the head of the Val Po under the northwest face of Monviso (in the Cottian Alps) through a delta projecting into the Adriatic Sea near Venice. It has a drainage area of 74,000 km² in all, 70,000 in Italy, of which 41,000 is in montane environments and 29,000 on the plain. The Po is the longest river in Italy; at its widest point its width is 503 m (1,650 ft).The Po extends along the 45th parallel north.
The river flows through many important Italian cities, including Turin (Torino), Piacenza and Ferrara. It is connected to Milan through a net of channels called navigli, which Leonardo da Vinci helped design.