The Danube River divides Budapest into the districts of Buda and Pest.
The river is Europe’s second-longest, flowing about 2,850 kilometers from Germany’s Black Forest to the Black Sea. It passes through or along ten countries, more than any other river in the world. Budapest lies near the middle of its European route and developed on both banks.
Buda occupies the hillier western side, while Pest spreads across the flatter eastern side. The two settlements were formally united with Óbuda in 1873, creating modern Budapest. Bridges across the Danube, including the Széchenyi Chain Bridge, became important symbols of the unified city.
The Danube is sometimes confused with the nearby Tisza when discussing Hungary’s rivers. The Danube is the larger international waterway and passes through four national capitals: Vienna, Bratislava, Budapest, and Belgrade. Its delta on the Black Sea is a major wetland and was designated a UNESCO World Heritage Site in 1991.