Long before satellites, a soldier who could read terrain could find a position within a few metres. The skill lay in matching what the map showed to what the ground actually did: a ridge line that fell away to the north, a stream that bent where the contours crowded together, a saddle between two hills. None of it required instruments beyond a compass. What it required was the patience to look at the ground and the map together until they agreed. Units that still teach the method argue that it is not nostalgia. Satellites fail, batteries run flat, and signals are jammed, and a navigator who has never learned to read ground has nothing to fall back on.