How many countries have a capital that stands on the River Rhine?

The Rhine is one of Europe's major rivers. It has its sources in Switzerland and flows in a mainly northerly direction through Germany and the Netherlands; it carries a large amount of traffic. 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 the Franco-German border, then flows through the German Rhineland and the Netherlands and eventually empties into the North Sea.

The capital cities of Switzerland, Austria, Germany, France and the Netherlands are not located on the Rhine. However, the capital of Liechtenstein is. Vaduz, the capital of Liechtenstein, has a population of about six thousand. Although it is the seat of the Liechtenstein parliament and is Liechtenstein's best-known town internationally, Vaduz is not the largest town; neighbouring Schaan has a larger population.