This is the Chablais, at the lower end of the Rhône valley near Aigle and Vionnaz, about a hundred kilometres south-west of the Swiss capital. This is where the great river, having run west through the Valais, turns north toward Lake Geneva, and the landscape is a mix of broad flat farmland, steep vineyards and bare limestone peaks, the Dents du Midi, whose serrated summits dominate the horizon to the south.
Aigle is a wine town with a castle, a pleasant old centre and slopes covered in Chasselas vines, which produce a crisp white wine that sells best in the cafes of the region. The castle, a handsome medieval fortress, now houses a museum of wine and the vine, and its tower has a view across the valley. The town also has an unexpected role in world sport. The headquarters of the international cycling union is here, with a velodrome and training centre, so on any given day you may meet professional cyclists on the roads.
Passes lead out of the valley in several directions. The Col des Mosses and the Col de la Croix, toward Les Diablerets, climb in smooth, wide bends through forest and pasture, with views of the glaciers above. The Col du Pillon, linked to the Glacier 3000 cable car, is another good ride, with good tarmac and gentle gradients. The Rhône valley itself is flat and busy with trucks, so the real riding is up the side valleys.
Bern, the capital, is worth a visit in its own right if you pass through. The old town sits in a bend of the Aare, with arcades, fountains and the famous clock tower, the Zytglogge, and bears are kept in a park by the river. It is a quiet and comfortable city that feels very unlike a capital.
Fuel is easy in Aigle, Monthey and the valley towns. Swiss speed limits are strict, with cameras at many exits. A motorway vignette is required on the A9. The best weather is from May to October, though autumn is lovely, with the vineyards turning golden and the first snow dusting the peaks.