We spent the whole day at San Diego Zoo, and we did not see all of it!
The zoo is spread over a large & hilly area which makes for some very nice open cage areas for some of the bigger animals – although many still are in quite small cages (including too many birds!). Animal highlights included: Hippos (Mum & “baby”), Polar bears, Meerkats (cute anyway, but especially so because they were being fed live crickets when we saw them, and were very animated chasing their meal around!):
In the late afternoon it started raining quite heavily – so we jumped on a bus that tours around the zoo, and stayed dry while getting a lift back to the entrance: