Huge zoo. Lots of things to do, to be honest proba...

Huge zoo. Lots of things to do, to be honest probably more than a days worth if you took it slow, especially if you wanted to tie it in with Balboa Park.
There's a tour trolley and a hop on hop off trolley, plus an overhead cable car which can help you get around. Lots of places to get food and snacks and water fountains to fill up water bottles.
The aviary where you can see hummingbirds was great.
The panda exhibit is the only one we came across with a queue and that took 30-40 minutes, so maybe do that first.
All in all a good experience and a good zoo