The Butterfly Pavilion (Westminster)
Cheyenne Mountain Zoo (Colorado Springs) — feed giraffes in the country’s only mountainside zoo
Colorado Gators Reptile Park (Mosca) — quirky, fun place with a lot to see
Colorado Wolf and Wildlife Center (Divide)
Denver Museum of Nature and Science (Denver) — nature dioramas, IMAX 3D Theater, Planetarium, all done well
Denver Zoo (Denver) — Typical big-city zoo, kept up but without a lot of flourishes
Downtown Aquarium (Denver) — sharks, rays, a tiger, the usual stuff—worthwhile on a day when being outside isn’t attractive
May Natural History Museum (Colorado Springs) — vintage exhibit of colorful and unusual insects
Pueblo Zoo (Pueblo) — small but pleasant zoo with a retro vibe.
Wild Animal Sanctuary (Keenesburg) — big cats and bears and such in big cages
CU South Denver Museum (Parker) — University of Colorado wildlife museum—not large, but fun do see.