The Grüntensee has a length of approx. 2.5 km and extends from the district Haslach in the municipality of Oy-Mittelberg to the municipality of Wertach. It is a reservoir of the river Wertach and has a circumference of approx. 8.2 km. A well-developed bike and hiking trail with a length of approx. 9 km leads around the reservoir.