The Main River holds the title of being the longest tributary of the Rhine, stretching across central Germany for a remarkable 525 kilometers before it joins the Rhine. Originating from the Fichtel Mountains in northeastern Bavaria, it flows through a diverse landscape, passing historic cities like Frankfurt am Main and Würzburg. The Main also plays a crucial role in the European waterway network, as it is part of the Main-Danube Canal, linking the North Sea to the Black Sea and facilitating a vital route for transportation and commerce.