Journey along the second-longest river in Europe. The Danube runs through 10 countries: originating in Germany, the Danube flows southeast, passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine before draining into the Black Sea. This educational virtual travel guide is based on the cities visited on your upcoming trip–”Passage Along the Danube”–Vienna, Bratislava, Budapest, Bucharest, and Belgrade.