Danube

The Danube glitters under clearing skies as it flows through Vienna, Austria. A traditional trade route since ancient times, the Danube traverses nearly 1,800 miles through Europe, from its origin in Germany's Black Forest until it drains into the Black Sea in Romania. While not the longest river in the world — or even in Europe — it holds the record for flowing through more countries than any other river (10). (Courthouse News photo / William Dotinga)