I like to think that we all have an inner child that enjoys the simple things in life. My inner child LOVES animals and visiting the zoo. The Cincinnati Zoo is by far one of the best zoos I've been to. Throughout the zoo are plants that constitute the botanical garden.
The zoo has encounter events for many of the animals, a special festival of lights during the holidays, and a 4D theater. They are also very active in educating people about animal welfare and conservation!
The Children's Hospital is really close, so when I had a membership I would walk down the street and have lunch at the zoo on nice days.