Receiving the Tisza in Serbia, this river begins in the Black Forest of Germany and is the second longest river in Europe.
This river's tributaries include the Iller and Abens Rivers. Previously, this river contained the Ada Kaleh, now submerged following the construction of the two dams at the Iron Gates. The confluence of this river and the Siret is at the port city of Galati, while this river joins a large tributary called the Sava in a Balkan capital. Receiving the Tisza in Serbia, this river begins in the Black Forest of Germany and is the second longest river in Europe. For 10 points, name this river that passes through Belgrade, Budapest, and Vienna, and flows into the Black Sea.
This river's tributaries include the Iller and Abens Rivers.
{Danube} River