Was I a seeing things? Nope, this WAS a road sign right in the middle of the river! The familiar triangle with a red trim and the symbol that warns you that the road is about to become narrow. Somebody went through a major effort and put it out there at low tide; I presume. A prank of some sort? Going home that night it was still sitting there - on a sand bank, as it were - even more out of place at low tide. The river is of course Nidelven, running through the city of Trondheim and into the Trondheim fiord.
