The longest Italian river is Po, which flows either  or  (considering the length of the right bank tributary Maira) and whose headwaters are 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. The vast valley around the Po is called Po Valley (Italian: ''Pianura Padana'' or ''Val Padana'') the main industrial area of the country; in 2002, more than 16 million people lived there, at the time nearly ⅓ of the population of Italy. The second longest Italian river is Adige, which originates near Lake Resia and flows into the Adriatic Sea, after having made a north–south route, near Chioggia.