The Rhine (German: Rhein [ʁaɪ̯n], French: Rhin, Dutch: Rijn, Walloon: Rén, Limburgish and Sursilvan: Rein, Sutsilvan and Surmiran: Ragn, Rumantsch Grischun, Vallader, and Puter: Rain, Italian: Reno, Alemannic German: Rhi(n) including Alsatian/Low Alemannic German, Ripuarian, Low Franconian: Rhing, Latin: Rhenus [ˈr̥eːnʊs]) is one of the major European rivers. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps, forms part of the Swiss-Liechtenstein, Swiss-Austrian, Swiss-German and then the Franco-German border, then flows in a mostly northerly direction through the German Rhineland and the Netherlands and eventually empties into the North Sea.
It is the second-longest river in Central and Western Europe (after the Danube), at about 1,230 km (760 mi),[note 1][note 2] with an average discharge of about 2,900 m3/s (100,000 cu ft/s).
The Rhine and the Danube formed most of the northern inland frontier of the Roman Empire and, since those days, the Rhine has been a vital navigable waterway carrying trade and goods deep inland. Its importance as a waterway in the Holy Roman Empire is supported by the many castles and fortifications built along it.
Among the largest and most important cities on the Rhine are Cologne, Düsseldorf, Rotterdam, Strasbourg and Basel.