A couple of weeks ago, while the weather was still warm, I brought the kids to Geneva Park District's Peck Farm Interpretive Center (4038 Kaneville Road, Geneva IL 60134 (630) 262-8244). We'd been there earlier in the year following a visit to Johnson's Mound, but it was March, and it was cold, and the exhibit I really wanted them to see was not yet open.
The Butterfly House is definitely worth a visit. It was thrilling to see about 15 different species of butterflies so close up. I'm now convinced that every home needs a honesuckle shrub. The butterflies were gaga over it.
At Peck Farm, you can also take a walk through a native plant prairie down to a pond, climb up into a silo, and have a picnic. A nice, inexpensive way to spend an afternoon.