Lagunen-Walzer (Lagoon-Waltz) op. 411 is a waltz by Johann Strauss II written in 1883. The waltz melodies are drawn from his operetta Eine Nacht in Venedig (A Night in Venice) which was a fiasco when premiered in Berlin on 3 October 1883. The waltz's primary melody was from the Act 3 song by the character Duke of Urbino. The Berlin production incorporated many outrageously silly lyrics during this waltz song where the singer has to sing the embarrassing 'Nacht sind die Katzen ja grau, nachts tönt es zärtlich Miau!' (At night, the cats are grey, at night "meow" they tenderly say!').