This river originally separated two cities that merged to become a central European capital.
This river is home to the enormous Huchen salmon. This river passes through two hydroelectric dams at the Iron Gates, which form part of an international border. A canal links this river to the more northerly Main ["MINE"] river. This river formed the Wachau valley, known for its wines and castles. Its tributaries include the Inn and the Prut. A city on this river is known for its Hofburg and Schönbrunn palaces. This river flows through both the Pannonian and Carpathian basins. This river originally separated two cities that merged to become a central European capital. For 10 points, name this river that passes through cities like Bratislava, Belgrade, Vienna, and Budapest before flowing into the Black Sea.
This river is home to the enormous Huchen salmon. This river passes through two hydroelectric dams at the Iron Gates, which form part of an international border.
the Danube [or Donau; or Dunav; or Dunarea; be very lenient with vowels]