just go to a music/folk festival and you'll see lots of 20~30 something naked chicks.
nude beaches are a mixed bag but if you find the right ones then same thing. just avoid the ones that old people would go to. younger people will walk/hike further to get to one.
most of the naked girls are hippies though.
/s/ sometimes has a naked festival/hippie girl threads and we get asked the same thing multiple times a thread, lots of good advice in those. i might start another thread later.