Natural regions of the Alpine Foreland

Hegau () either refers to a region of the Duchy of Swabia or to only that part of said region which is presently located in the country of Germany. It is known for its extinct, partly eroded volcanoes, most of which are crowned with ruins of medieval fortresses.

thumb|400px|The Gäuboden thumb|left|Gäuboden landscape with Oberalteich Monastery in the background