Brookfield Zoo (sponsored by Meijer) is giving free admission to all kids 11 years old and under between 8/16-8/18. Adults will still have to pay admission and parking.
This is a great opportunity, but let me just give you a warning based on experience – it is going to be completely nuts there. We are members (one of the things we splurge on because we go a lot) and I have been there a number of times when there was no parking left and there will be people wherever you look. My advice is to get there first thing in the morning (they open at 9:30) or towards the end of the day (they close at 6pm). Have fun!
(Thanks Mummy Deals!)