The Honolulu Zoo is situated where Honolulu blends into Waikiki. It's on a main street of which one side one of the more famous beaches on Oahu, and the other side is full of stores such as Coach, Prada, etc.
Although it's situated in an urban environment, the Honolulu Zoo has plenty of attractions, including plenty of animals, a park for the little ones, a restaurant, gift shop, etc.
It has its own dedicated parking lot of pay-per-hour parking spots, but they tend to fill up quick with the beach right across the street. If you do go, try to go early in the morning, before all the tourists take over!
Local? The Honolulu Zoo has a society you can join for about $40/yr that will get you, your family, and friends in without charge year-round, discounts on food/gift store items, special society-only events, and more!