Grüntensee, Reservoir in the Allgäu, Bavaria, Germany

Grüntensee is a reservoir in the Allgäu region of Bavaria, held back by a dam built at the foot of the Grünten mountain. The shoreline is mostly wooded, with open views toward the surrounding Alpine foothills on clear days.

The reservoir was created in the mid-20th century when a dam was built across the valley to generate electricity for the surrounding region. The construction was part of a broader effort to develop hydroelectric power across Bavaria after World War II.

The lake takes its name from the Grünten, the mountain about 11 km to the southwest on the northern edge of the Allgäu Alps. The northern shore holds the Kletterwald Grüntensee, a high ropes course, and the southern shore has a small patch of houses with a playground near the water. The east shore was a filming location for the 2011 ZDF television film Klarer Fall für Bär, starring Hans Sigl.

The area is easy to reach by car, and parking is available close to the dam. Walking paths run along the shore and give a good sense of the size of the lake and the surrounding hills.

The lake takes its name from the Grünten, the mountain about 11 km to the southwest, not from a peak directly above the water. In 2011 the eastern shore served as a filming location for the ZDF television film Klarer Fall für Bär, starring Hans Sigl.