We have a zoo about 20 minutes from us, and it's a decent size and it's pretty nice. There are other ones within an hour or two, but we haven't visited those ones yet.

Admission for our local zoo is $10 per adult, and $8 per kid. So $36 for our family of 4 to visit the zoo. I think if we feel we will go more than twice this year we should get an annual pass. I think those run $80-$100 for a family.