There is a lido with SUP (Stand Up Paddle boards) rental directly by the lake, a swimming area and a restaurant neraby.
The lake is very popular in the summer heat, which is why there can be a shortage of parking spaces. Then you can just continue on the same road to reach lake Schluchsee in few more minutes.
Some facts about lake Windgfällweiher: The lake was enlarged to its current size in 1895. It is now 700 m long and 400 m wide. Some of the water from the Feldsee Lake first flows through the Windgfällweiher before reaching the Schluchsee Lake.