The second longest river in Europe, the Danube originates in Germany and drains into the Black Sea
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/danube
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/down-earth
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution