The Johnson County Historical Society Museum sits just outside Iowa City in Coralville and fills in the local history around the university-centred story downtown. Its collections cover settlement, transport, civic life, domestic objects, and the small institutions that shaped Johnson County.
It is a specialist stop, but a useful one if you have already seen the Old Capitol and want the less ceremonial version of local history. Pair it with Coralville's riverfront or the Antique Car Museum of Iowa when you are exploring beyond the Pentacrest.