The Rhine (Rhein in German) (Rhin in French) (Rijn in Dutch) river 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 1230 km (760 mi), with an average discharge of about 2900 m3/s (100.000 cu ft/s)
The Rhine and the Danube comprised much of the Roman Empire’s northern inland boundary, and the Rhine has been a vital navigable waterway bringing trade and goods deep inland since those days. The various castles and defenses built along it attest to its prominence as a waterway in the Holy Roman Empire. Among the largest and most important cities on the Rhine are Cologne, Düsseldorf, Rotterdam, Strasbourg and Basel.