[Gravdigr]

In the first episode of Hinterland (which takes place in Wales) the story of (a) Devil's Bridge is told.

A woman has lost her dog, that happens to turn up on the far side of an uncrossable river.

The woman is at a loss as to how to recover her beloved dog.

The devil his own self shows up and offers to help the woman by building her a bridge to cross the river and, thus, recover her beloved pet. The devil, always looking for souls, tells the woman the cost of the bridge will be the soul of the first person to cross it, and that he will take her soul when she crosses the bridge in the morning.

The woman gets to the river the next morning, and sure enough, there's a big nice bridge spanning the river. Seeing her dog on the other side of the river, she reaches into her bag and pulls out a fresh-baked loaf of bread, calls to the dog, and tosses a piece of bread halfway across the bridge. The dog, being hungry from not having eaten, goes to the piece of bread. When he's eaten it, she shows him the rest of the loaf, calls to him and the dog crosses the rest of the way and the woman goes home with her dog, having cheated the devil out of her soul.

The devil was so embarrassed at being cheated by the old woman that he never set foot in Wales again.

Or something like that.