Possible Clues:

• River that flows through or beside 10 countries
• Major European river flowing into the Black Sea
• Longest non-Russian river in Europe
• River that flows through Vienna and Budapest
• Beaune, not the ultimate in wine, drunk with date and flowing water
• Bad painting to include north European flower
• Undeniable muddle as Nile disappears into another river?
• Scandinavian bridges for all to see over top of Bergen river
• Content of tube fills European river
• European river ban due for review