Lincoln Park Zoo still has free entrance, but, everyone trying to visit Lincoln Park Zoo must go onto their website & register for free tickets
Make a reservation on their website.
Yeah due to COVID-19 you currently have to preorder free tickets on the website. It does not matter what time slot you choose your tickets are good all day long.
No calls needed. Just make a registration online. It's simple and free. But registration is the only way to enter the park. They will check the registration code and allow entry. No more formalities other than this
You need to make an appointment online but still free
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