Yes there are a couple of naturist beaches around benidorm, one, cala del ti ximo is behind rincon de loix (under the cross on the mountain) and is populated mainly by gay men. However, it's not all black and white. Public nudity in spain is, in fact, legal
Lucette Romy Nude & Sexy Photos | #The Fappening
This means that technically, you could even walk around the streets of madrid in your birthday suit if you so desired