The 도나우 River, known as the Danube in English, is the second-longest river in Europe, flowing through ten countries. It stretches approximately 2,860 kilometers, starting in Germany and passing through countries like Austria, Hungary, and Serbia before emptying into the Black Sea. The river is significant for its historical and cultural importance, serving as a vital trade route for centuries. It is also home to diverse ecosystems and numerous cities, including Vienna and Budapest, which are famous for their beautiful architecture and rich history along the riverbanks.