Danube
The Danube was once a long-standing frontier of the Roman Empire, and today flows through 10 countries, more than any other river in the world. Originating in Germany, the Danube flows southeast for , passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova and Ukraine before draining into the Black Sea. Its drainage basin extends into nine more countries. The Danube river basin is home to fish species such as pike, zander, huchen, Wels catfish, burbot and tench. It is also home to a large diversity of carp and sturgeon, as well as salmon and trout. A few species of euryhaline fish, such as European seabass, mullet, and eel, inhabit the Danube delta and the lower portion of the river.
List of crossings of the Danube
This is a list of crossings of the Danube river, from its source in Germany to its mouth in the Black Sea. Next to each bridge listed is information regarding the year in which it was constructed and for what use it was constructed (foot bridge, bicycle bridge, road bridge or railway bridge), and the distance from the mouth of the river in kilometres where available.