The Haldensee lies approximately 1 km west of the valley watershed between Vils and Lech and occupies the entire width of the valley floor. Accordingly, the shores drop steeply to the north and south, while they are relatively flat to the east and west.[2] Its outflow is the Berger Ache to the Vils in the west; the main tributaries are the Gessenbach in the southeast and the Strindenbach in the southwest. Near the western shore lies the village of Haldensee (municipality of Grän), and at the northeastern end lies the village of Haller, which belongs to the municipality of Nesselwängle. The Tannheimer Straße (B 199) runs along the northern shore.