In the centre of Basel, the first major city in the course of the stream, is located the "Rhine knee"; this is a major bend, where the overall direction of the Rhine changes from West to North. Here the High Rhine ends. Legally, the Central Bridge is the boundary between High and Upper Rhine. The river now flows North as Upper Rhine through the Upper Rhine Plain, which is about 300 km long and up to 40 km wide. The most important tributaries in this area are the Ill below of Strasbourg, the Neckar in Mannheim and the Main across from Mainz. In Mainz, the Rhine leaves the Upper Rhine Valley and flows through the Mainz Basin.
What is the first major city in the stream of the Rhine? What is the bend of Rhine in Basel called?  What is the boundary between the High and Upper Rhine?  How long is the Upper Rhine Plain? How wide is the Upper Rhine Plain?  What is the first major city in the course of the Rhine? What is the first major bend in the Rhine called? The bend on the Rhine goes from the West to what direction? What ends at this bend in the Rhine? What is the legal boundary behind the High and Upper Rind?