Lapping the shores of Germany, Switzerland, and Austria, the Bodensee (Lake Constance), at 65 km (40 mi) long and 15 km (9 mi) wide, is the largest lake in the German-speaking world. Though called a lake, it's actually a vast swelling of the Rhine, gouged out by a massive glacier in the Ice Age and flooded by the river as the ice receded. The Rhine flows into its southeast corner, where Switzerland and Austria meet, and flows out at its west end. On the German side, the Bodensee is bordered almost entirely by the state of Baden-Württemberg (a small portion of the eastern tip, from Lindau to Nonnenhorn, belongs to Bavaria).
A natural summer playground, the Bodensee is ringed with little towns and busy resorts. It's one of the warmest areas of the country, not just because of its southern latitude but also owing to the warming influence of the water, which gathers heat in the summer and releases it in the winter. The lake itself practically never freezes over—it has done so only once in the last two centuries. The climate is excellent for growing fruit, and along the roads you'll find stands and shops selling apples, peaches, strawberries, jams, juices, wines, and schnapps, much of it homemade.
Visit the Travel Talk forums for help on planning your trip