The Danube is the second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest south into the Black Sea. A large and historically important river, it was once a frontier of the Roman Empire. In the 21st century, it connects ten European countries, running through their territories or marking a border. Originating in Germany, the Danube flows southeast for 2,850 km (1,770 mi), passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine. Among the many cities on the river are four national capitals: Vienna, Bratislava, Budapest, and Belgrade. Its drainage basin amounts to 817,000 km² and extends into nine more countries.
The Danube in Budapest
The hydrogeographical source of the Danube at St. Martin's Chapel in Furtwangen im Schwarzwald: the Bregquelle, the source of the Danube's longest headstream, the Breg, where the Danube is symbolized by the Roman allegory for the river, Danuvius.
The symbolical source of the Danube in Donaueschingen: the source of the Donaubach (Danube Brook), which flows into the Brigach.
The Tisza is the longest tributary of the Danube.
Central Europe is a geographical region of Europe between Eastern, Southern, Western and Northern Europe. Central Europe is known for its cultural diversity; however, countries in this region also share historical and cultural similarities.
The Pannonian Plain, between the Alps (west), the Carpathians (north and east), and the Dinaric Alps (southwest)
Geopolitical Challenges – Panel on the Future of Europe
Habsburg-ruled lands (divided between Cisleithanian/Austrian-administered and Transalthanian/Hungarian-administered)
Travel time by car or ferry from the geographical center of Europe