A beautiful park with a fairly large lake in the middle. There is also a running track with a football pitch and a Japanese garden. The lake was once a quarry, so it is quite deep (82 feet) and the drop-off from the shore can be sudden and steep, so small children need close supervision. The west end of the lake is more friendly to smaller kids, with a large, shallower area. Otherwise, one can just jump in anywhere they like. Being Germany, there are no life guards or restrictions. People even dive and jump off the pontoon bridge.
Also, being Germany, there is nudity. There is no official FKK site, but there is a small area on the north shore here that has become an unofficial FKK area. It is visible from the walking path that circles the lake and some people hang out in the area with bathing suits on, which would not be tolerated at an official FKK site. Still, plenty of people of all ages (including families) were comfortable enough to go au naturel when I was there, so when in Rome (or Freiburg)...
If you're looking for a more private and/or egalitarian FKK experience, seek out a nearby lake with a sanctioned site.
There is a Biergarten on site at the west end of the lake. The curry wurst is just ketchup with curry powder sprinkled on it but the prices are reasonable. There is a tower to explore and a stage right on the water where a traditional oom-pah band was playing for a bit.
The southeast end of the lake is easily accessible by the #1 Tram and of course the entire park is accessible by bike. I don't know about car parking in the area. read more