A museum dedicated to the Nibelungenlied, the 13th-century Middle High German epic that sets much of its action in Worms. The medieval Burgundian royal court of the poem was here; Siegfried, Kriemhild, Brünhild, and the treacherous Hagen are all local characters in spirit.
The museum is unusual: it occupies two original 12th-century town-wall towers and is presented almost entirely as an audio walk, with carefully written narration in German or English playing through headphones as you climb the towers. No artifacts, no objects, just the story and the medieval space. Lasts about 90 minutes. The view from the top is excellent.