Rhine

 VisuRiS — associated with Waterways of Mainland Europe

The official inland waterway resource for Belgium with actual traffic and planned operations on the waterways. Also has voyage planning and notices to mariners

Wikipedia has a page about Rhine

The Rhine (German: Rhein [ʁaɪ̯n], French: Rhin, Dutch: Rijn, 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 [ˈr̥e̞ːnus]) is one of the major European rivers, which has its sources in Switzerland and flows in a mostly northerly direction through Germany and the Netherlands, emptying into the North Sea. 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 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), 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. In the modern era, it has become a symbol of German nationalism.

Among the largest and most important cities on the Rhine are Cologne, Düsseldorf, Rotterdam, Strasbourg and Basel.