Are you the member of a local zoo? Our local zoo has a reciprocal relationship with many North American zoos and Toronto Zoo is one of them. We get 50% off admission there (I live in Seattle but I only know this because we have family in the Toronto area so there's a chance we might actually use it in Toronto one day). If you have a zoo in your area, they are probably involved in a similar relationship. You will have to buy a membership, but they normally pay for themselves in 2-3 visits. My family spends a lot of time at the zoo, so our membership pays for itself in a couple weeks.