Use an OS Map and a game of battleships for cubs to be given a reference to locate on the map.
OS Map of the area, pre-selected co-ordinates for interesting locations and reference points on the map, a battleships grid (8 by 8) with a grid reference in some of the squares, a blank grid so they can mark where they have tried.
The cubs completed an obstacle course and as each completed they get to take a shot at the grid. If they don't score they have to go back and do the obstacle course again to have another go. If they get a hit then they have to find out what they have hit by finding the location on the map and writing it up on a board or sheet of paper.