If you ever hear about how awesome the San Diego Zoo is, believe what you hear.
More generally the zoo is designed well. Almost all the enclosures are set so that the animals are close to the visitors, while having plenty of space to live in. I’ve never seen hippos this close before for instance.
There’s a huge variety of animals to boot. And many colorful plants. If I have any complaint, it’s that it was just too big—in the six hours we were there we still didn’t get to several exhibits we wanted to, such as they naked mole rats and the hyenas. But that, of course, is a trivial complaint.
(All photos are mine. Feel free to use, but please give me credit).