What Ernie Mertins said is right, but you also pay about $3 in parking. Check places like Groupon to try and find some discounts. Though, when we went, it seemed like tickets were cheaper when we got them in persom, about $10 or so in fact. Call and ask.
If you plan on going more than twice in the course of a year i would buy a membership. It offers a 2 parent plan with up to 4 kids i believe for about $110. It will give you a discount on all purchases inside the zoo as well.
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