The Sophia M Sachs Butterfly House, run by the Missouri Botanical Garden, occupies a glass conservatory in Faust Park, about 30 minutes west of downtown. The central conservatory holds around 1,000 free-flying tropical butterflies from 60 species, in an environment kept at 80°F and 70% humidity year-round.
Visitors enter through an air-locked vestibule and emerge into a tropical garden filled with butterflies that land on shirts, hats, and outstretched fingers. The morning emergence chamber — where pupae open and adult butterflies dry their wings — is the most interesting time of day. Outside, smaller exhibits cover bees, beetles, and butterfly conservation. Modest admission fee. Best for an hour or two with children.