Marked clearly on the Down Survey maps of 1655-6, which documented Irish lands following the Cromwellian conquest, the castle appears on both the parish maps of ‘Clonetubrid and Glasshicroe’ and ‘Belanemarra’, alongside three houses that once formed a small settlement. These detailed surveys, now held by Trinity College Dublin, provide some of the only visual evidence of the castle’s existence and location.

By 1969, local historian O’Kelly recorded that the castle had largely vanished, noting that it once stood in what locals called the Cellar Field; a name derived from the castle cellar that remained visible at the time. A field inspection in 1987 placed this location southeast of Sart crossroads, though even then the castle itself had disappeared from view. Today, visitors to the site would find no obvious ruins above ground, but modern technology has revealed something the naked eye cannot see.

Satellite imagery from 2018 shows a large rectangular cropmark in the field immediately south of where the castle once stood. This ghostly outline, visible only from above, likely marks the location of a bawn; the defensive courtyard wall that would have protected the castle and its inhabitants. These crop marks occur when buried stone foundations affect plant growth above them, creating patterns that reveal lost structures. While the castle of Sart may have crumbled away, its defensive walls have left their signature in the very grass that grows above them, a reminder that Ireland’s landscape holds countless stories just beneath the surface.