In Spain, several Roman aqueducts (Segovia, Tarragona and some other more minor works of civil engineering, I believe) are often known as 'the devil's bridge' or similar, with an associated legend about the devil himself building it in one night, for a bet, or as a ruse.

The origin, I presume, is that in the early Dark Ages, the feat of engineering involved seemed so utterly impossible for human hands that it could only be ascribed to a supernatural figure.