An example of dramatic irony in act 1 scene 6?

Duncan is on his way to Inverness to be hosted by Macbeth. Duncan senses the air is gentle around Macbeth's castle. The audience, however, knows that Macbeth and L. Macbeth are planning to murder Duncan that night.

Duncan: This castle hath a pleasant seat. The air Nimbly and sweetly recommends itself Unto our gentle senses.