Thank you so much to everybody for your interesting recommendations. It's really hard to find a matching place if you are not a big fan of club vacations and if you're more into places that are close to nature and less touristy. It's kind of sad that we almost don't have any of those places here in Germany so thank you again for your suggestions all over Europe.
It's kind of sad that we almost don't have any of those places here in Germany
This answer surprised me, so what can I say about only one official naturist center in Poland? If you care more about nature and nature, you can take a chance on Koversada, because it is really beautiful, but the infrastructure is quite outdated. Alternatively, I can also recommend the Solaris campsite, in its final part the nature is very impressive, the beaches are nice and the infrastructure is better than in Koversada. Among smaller campsites with beautiful and wild nature, I also recommend the "Nudist" campsite on the island of Hvar, Bunculuka on the island of Krk, Baldarin on the island of Cres and the Kanegra campsite on the border with Slovenia. In Germany, I really like the FKK Ostsee campsite, although I haven't been there because the weather is unpredictable.
We do not have nudist resorts in Germany. We have campsites, like Rosenfelder Strand. Nobody invested yet in nudist resorts. Also the german policy, to have almost no nudist commerzialisation. And I think the german weather plays also a role. It would be to risky to build up a german nudist resort. Could be that nobody visits it, because of the rain.