Prague's Museum of Public Transport fills an old tram depot with beautifully kept trams, trolleybuses, buses, and service vehicles. The best pieces trace the city from Habsburg-era four-wheelers through the red-and-cream Tatra cars that still feel like part of Prague's identity.
It is especially good with children or anyone who likes cities through their transport systems. If the building looks shut during posted hours, try the metal door at the far-left arch.