Are you coming into the zoo? means something like Bejössz az állatkertbe?, that is when you're asking someone who is standing outside to come in.
Are you coming to the zoo? is a better fit for Jössz/Eljössz az állatkertbe?
Yes, Jössz/Eljössz az állatkerthez? is also possible, and it will be "to the zoo" as well. But I think, from context, if you ask someone Are you coming to the zoo? you also mean going in, not just standing next to it.