The Butterfly Gardens of Wisconsin is "Wisconsin's largest butterfly house and maze." They also have bee, frog, toad, and turtle exhibits. The butterflies look to be housed in a greenhouse-like structure, while the maze is shaped like a butterfly through the garden.
It looks like an enjoyable, relaxing stop. I believe they are open seasonally.
Butterfly Gardens of Wisconsin
N2550 State Hwy 47 ~ Appleton, WI ~ 920-475-0777
Admission: $6/adult, $3/child, 2 & under free