Bernese Alps through which the Rhône finds its way to Lake Geneva, to the Grimsel Pass or, depending on the definition, to the river Reuss (thus including the Uri Alps). The principal ridge, a chain that runs from west (Dent de Morcles) to east (Sidelhorn), whose highest peak is the Finsteraarhorn, forms the watershed between the cantons of Bern and Valais. Except for the westernmost part, it is also the watershed between the Rhine (North Sea) and the Rhône (Mediterranean Sea). This chain is not centered inside the range but lies close (10 to 15 km) to the Rhône on the south.
Swiss Plateau the southwest, the Swiss Plateau is confined by Lake Geneva, in the northeast, by Lake Constance and the Rhine. Geologically, the Swiss Plateau is part of a larger basin that extends beyond the border of Switzerland. At its southwestern end, in France, the plateau, in the Genevois, ends at Chambéry where Jura and Alps meet. At the other side of the Lake Constance, the plateau continues in the German and Austrian Pre-Alps. Within Switzerland, the Swiss Plateau has a length of about , and its width increases from the west to the east: In the Geneva region, it is about