When our family lived right off Ocean Beach, the local SF Zoo was just blocks away from us. Nightly, it started, at 1 Am, the pitiful wailing of those wild animals locked inside the Zoo grounds. It sounded like they wanted out, and were planning their escape. The loudest, were the high pitched monkey screams, that pierced the fog drenched nights in that area.  Simon & Garfunkel , said it best, 'It's all happening at the Zoo, I do believe this, I do believe it's true...'