The Feldsee is a lake in southern Baden-Württemberg at the foot of the Feldberg east of Freiburg im Breisgau in Germany. It is part of the Southern Black Forest Nature Park.
Wikipedia https://en.wikipedia.org/wiki/Feldsee
More info (German) http://schwarzwald.region.org/feldberg/feldsee.htm
Address 79868, Germany
Coordinates 47°52'13.993" N 8°1'47.759" E