britpicking bleg

Help I have to make a narrative/setting decision and I'm stuck. If I have some twenty-something English kids going to a small art exhibition in Soho in the late 1980s, and I want to have them also go to a park, does it make most sense for me to send them to Regent's Park, Hyde Park or St. James Park? Can either be for lunch in the afternoon or later at night. Nature personification deities are involved, so location/resonance matters.