Wagner's first inspiration was for an opera (Siegfried's Tod, projected in 1848) on the death of Germany's mythical hero; but he found that the story needed a preliminary drama to convey its antecedents.
Siegfried's whole character and career is, indeed, annihilated in the clumsy progress towards this consummation; but Shakespeare might have condoned worse plots for the sake of so noble a result; and indeed Wagner's awkwardness arises mainly from fear of committing oversights.
Gotterdammerung: der Ring des Nibelungen, dritter Tag; introduction and 3 acts (Siegfried's Tod already sketched dramatically in 1848; music, 1870-1874).
For use in the field, however, and for scientific work, a contoured map like Siegfried's atlas of Switzerland, or, in the case of hilly country, a map shaded on the assumption of a vertical light, will prove more useful than one of these, notwithstanding that truth to nature and artistic beauty are claimed on their behalf.
The story of Siegfried in Richard Wagner's famous opera-cycle Der Ring der Nibelungen is mainly taken from the northern version; but many features, especially the characterization of Hagen, are borrowed from the German story, as is also the episode of Siegfried's murder in the forest.