Farm lovers, your cup overfloweth! Going the other way there is Capel Manor farm in Crystal Palace park. It's not huge, but we had a great time there a couple of weeks ago. They have a timetable of "handling" sessions where the keepers get the animals out for you to touch/feed. They have quite a few reptiles/amphibians/fish, as well as furry stuff and farm animals. The corn snake was good, but I drew the line at the giant African land snail (I noted that the keeper was wearing a latex glove!)