Also some strange thing is the fact in the Netherlands that even when less young girls/woman are going to a nude-beach, you can still see a lot of nice girls/students/woman laying all nude in the garden(s), which most Sauna/wellness centers have here. In the safe guarded garden of a sauna/wellness center they feel comfortable enough to go all nude. That means that there still a lot of potential female nudists but for several reasons rather choose to go topless on the beach.
