If you started at this river's source in Germany and wanted to follow it to its end, you'd end up at the Black Sea. What is the name of this second longest river in Europe?

The Danube River is the second longest river in Europe after the Volga River in Russia. It served as the northern boundary of the Roman Empire for a time, and some of Europe's major cities were settled during that time along its banks such as Vienna, Budapest, and Belgrade.

Asked by Jason Forbes · Last updated 5 years ago · 196.4K views · SOURCE