Hachures, the short radiating lines cartographers use to suggest a depression or slope, implied something worth noting: a hollow in the landscape, distinct enough from the surrounding terrain to be recorded. When someone finally went to look in 1983, half a century after the map was drawn, they found a tree-planted hollow, almost certainly the remains of a disused sand or gravel pit.

There is something quietly telling about that fifty-year gap. A feature gets mapped, interpreted, and filed away, and only later does a physical inspection reveal what it actually is. The pit itself probably dates from after 1700, dug at some point to extract sand or gravel for local construction or road-making, the kind of small-scale industrial mark left on a landscape and then gradually absorbed by it. By the time anyone looked closely, the forest plantation on the bogland top had done its work, and the hollow had become part of the tree cover rather than an obvious wound in the ground.