Clarification Please

In the 60s and 70s (and earlier?), did the phrase "walking through the park" mean something other than what it reads? Was it like, a euphemism for some crazy sex act? drug culture slang for... doing drugs? some bizarre pagan animal sacrifice? (As in, "hey baby doll, me and these here crazy hep-cats gots a black-market goat we plan on offing for the greater good - ya dig?")

For a phrase so innocent and innocuous sounding, it has been used in so many blues songs, and the hard rock songs that rip off said blues songs, that I find it hard to believe it simply means going for a stroll in Public Gardens. Google and the Urban Dictionary turned up nothing, so yeah - if any groovy old cats read this blog some clarification would be fantastic. Thx.

Somewhat related - I'm slowly going through the discography of The Black Keys in preparation for the Concert on the Hill in July (see below). Very nice.