On the facade of the building Zelenih beretki 22a, Sarajevo one can see the following coordinates:
43° 50' 50" NORTH 18° 23' 1" EAST
These coordinates are definitely not new, but were put on the facade probably when the building was finished. Since the posted coordinates are about 3652 meters (3446 meters West and 1211 meters South) from the current position, it is probably referring to a different, older coordinates system.