There are currently no laws against nudity in public in Spain, which means that you can go anywhere in the country naked.  Knowing when it's appropriate to go clothing-free comes down to understanding the Spanish culture as it relates to being naked. While Spaniards don't find women's breasts taboo like Americans, going fully naked it still considered inappropriate it most public settings. Many of Spain's beaches are nude-friendly, so no matter where you go in the country, there's a chance you can take your tops (and bottoms) off without fear. Just  check on what everyone else is doing around you before you disrobe or just look for a quiet spot a little further.