Hachuring, a method of indicating sloped or disturbed ground through short radiating lines, was a standard tool for suggesting topographic irregularity without spelling out its cause. Whatever the original surveyors made of it, the feature was recorded and left to future interpretation. When someone finally went to look in 1984, more than half a century after the map was drawn, they found a disused and heavily overgrown gravel pit, long since abandoned and swallowed back into the landscape.