I visited the Sophia M. Sachs Butterfly House in St. Louis County Missouri with @RatioTile back in June. It is a nice little place with a couple terrariums and a lovely butterfly pavilion. Not really a place to go out of your way for, but a nice stop if you are in the St. Louis area already.
I...
The Endeavour Tropical House began life as the Sir Joseph Banks Conservatory near Lincoln Castle. It closed in 2014 and was donated to the zoo in 2016, which then converted it into a butterfly house.