Back in 2007, the Spanish Naturist Federation (FEN) launched an initiative called Day Without Bathing Suits (Día Sin Bañadores) geared to all Spaniards and tourists in Spain, that was to be held on the third Sunday in July. As it turned out, the initiative was highly successful the 2010 Word Congress in Italy aproved this day as an International day.
This year it's being celebrated next Sunday July 20skinnydip3_2_s. The idea is to invite people that aren't regular nudists to take off their bathing suits and enjoy the natural outdoor life. As you know, the laws in Spain allow for freedom of choice in dressing; that is, whether wearing any kind of suits or to being in the nude in any public space, unless there's specific legislation against it.
Since it started, the campaign has been a success. Being that wearing a bathing suit is an option, the respect should be mutual: “I do not make you take your clothes off, you should not make me put them on.”
Find out more at http://nudeinspain.com/blog/nudist-events/day-without-bathing-suits-2014