Not sure. The wikipedia article is quite interesting.. (1) At least when I was a kid, in Germany, it was very common culture to go swimming in the lake without clothes, and with the whole family. (There was a section on that lake where you had to wear bathing clothes. It was nearly empty.)

(1)http://en.wikipedia.org/wiki/Naturism (also contains pictures of naked people, Sherlock)

edit: Reading on in the German article.. it states that the market for nudist holidays in Germany is estimated to be around 10 million people, 1/8th of the population. Also, Germany seems to be the most relaxed of the Western countries in this issue. The history is quite interesting.