The Lower Saxony Asparagus Museum is more fun than the name may suggest. Set in an old Low German hall house by the Quaet-Faslem-House, it follows asparagus from field to table, with tools, machines, and the rituals of the spring season.
It works because Nienburg really is asparagus country. Visit in season and the museum stops feeling like a curiosity and starts to explain half the menus and market stalls in town.