The Darmstadt Railway Museum (Eisenbahnmuseum Darmstadt-Kranichstein) occupies a preserved 1890s engine shed in the Kranichstein district, northwest of the centre. The collection focuses on the history of the German railway network, with particular attention to the state railways of Hessen and the pre-war Reichsbahn.
The exhibits include a dozen or so full-size steam and diesel locomotives, historic carriages, signals, tools, and an extensive display of railway memorabilia. Unlike many transport museums, this one has a lived-in quality — the volunteers are passionate and knowledgeable, and you may well end up in a long conversation about the finer points of German locomotive history if your German is up to it.
The museum is open on selected weekends, with steam-hauled excursions on special event days. Check the museum's own website for the current schedule before visiting. Located at Kranichsteiner Straße, accessible by tram from the city centre.