Hachures, the short radiating lines that cartographers used to indicate slopes or depressions, suggested something worth noting in the landscape, though the map offered no further explanation. It was not until an inspection in 1984 that the feature was identified on the ground: a disused sand pit, its edges dropping away in a steep-sided gully, the kind of small extraction site that once supplied raw material for local building and drainage work without ever attracting much documentary attention.

The pit is thought to date from the nineteenth or early twentieth century, a period when modest quarrying and sand extraction were ordinary features of the rural Irish landscape, carried out at a local scale to meet immediate practical needs. Such sites rarely left much of a paper trail. They appear briefly in cartographic records, are worked for a generation or two, and then fall quiet, their edges softening over time while the surrounding land absorbs them back into the ordinary texture of the countryside. The Knockanarra pit fits that pattern precisely, visible enough in 1930 to earn a place on the map, and unworked long enough by 1984 to require close inspection before its original purpose became clear.