Upper Rhine Plain

The Upper Rhine Plain, also called the Rhine Rift Valley or Upper Rhine Graben, is a major rift about 350 kilometers long and 50 kilometers wide on average, running from Basel in the south to Frankfurt and Wiesbaden in the north, with its southern section straddling the France-Germany border. It forms part of the European Cenozoic Rift System across Central Europe, having formed during the Oligocene in response to the rise of the Alps to the south, and it remains active today as a downfaulted trough through which the Rhine flows. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/