At the end of South Street in Exeter, straddling a gap in the city wall is a bridge that has cables as expensive and dubious decoration.
From here it looks to make some sort of sense (though the relative positions of cable, leg and cantilever end are strange) but the end view begins to confound that.
Here we see that the back-stay cables go straight to the ground straddling the wall, some of which is Roman.
From here you can see how much those cables sag. Natural frequency about 0.5Hz as I recall, easily measured with a watch anyway.
Where does the reaction go though?
Answer seems to be nowhere, or at least in bending into that column so it is well there is no tension to speak of.