Konstanz is the German city that sits on Switzerland's lap, so close to the border that the two towns, Konstanz and Kreuzlingen, run into each other with a fence in between. The old town lies on the narrows between the Obersee and the Untersee, the two halves of Lake Constance, where the Rhine leaves the lake, and it has one of the best preserved medieval centres in southern Germany. Its survival has a simple explanation: it was not bombed in the Second World War, partly because of its closeness to neutral Switzerland. In the early fifteenth century, it hosted the Council of Constance, which ended a split in the Catholic Church and condemned the reformer Jan Hus, who was burned at the stake in 1415.
The pile-dwelling remains at Wollmatingen-Langenrain are the older story, and they belong to the UNESCO listing of prehistoric pile dwellings around the Alps. They date from the Neolithic and Bronze Age and lie preserved under the shallows near the nature reserve of the Wollmatinger Ried, a huge reedbed on the lake shore that is one of the most important bird habitats in central Europe. Nothing is visible from the land, but the reedbeds, with their thousands of waterfowl, are a spectacle in autumn and winter.
The roads around the Untersee are among the nicest in the region. Cross the border into Switzerland, and the road follows the shore through Tagerwilen and Ermatingen, with orchards, vineyards, villas and views of the lake and the green island of Reichenau, which holds a UNESCO-listed monastery with Carolingian wall paintings. The corners are gentle and the scenery is pastoral, with the Alps visible on a clear day to the south. Weekend traffic is heavy in summer, with cyclists and families, so go early. In autumn, the fruit stands sell apples and pears, and the vineyards turn red and gold.
Konstanz has plenty of fuel and restaurants, and Tagerwilen is a few minutes away. Check the border formalities before you cross, as you will need your passport, and remember that the Swiss motorway vignette applies to motorbikes. Try the lake fish, Felchen, fried in butter, and a glass of local wine.