The Historisches Museum, in a complex of buildings on the southern edge of the Römerberg, tells the story of Frankfurt from its Roman origins to the present. The 2017 reopening — after a decade-long rebuild — produced one of the most thoughtful city museums in Germany, with floors arranged around questions ("What is Frankfurt? Who is Frankfurt?") rather than chronology. Highlights include the 9-square-metre Snow White-style cabinet model of the entire city, the medieval Saalhof and Bernuspalais wings, and rooms on the rebuilding of the city after 1945.
A separate Kindermuseum branch in the same complex is one of the better children's museums in Germany — interactive, well-designed, and unusually serious about local history. The whole museum complex is included in one ticket. Tuesday to Friday 10am to 6pm, weekends 11am to 7pm.