The place isn't well signed around, it's good to have a guide which isn't too expensive ang gives you a better idea of the place. Bring some fruit for the animals and you'll avoid overpaying for them inside. Also, you'll make them happier, the love these snacks.
Botanic Garden was pretty and clean, the zoo on the other hand was a bit of a sad look. I don't like caging animals as they're rarely taken care of properly, here you have an impression of concrete nature everywhere...