The castle appears on the 1908 Ordnance Survey six-inch map, marked in the southwest quadrant of what archaeologists classify as a motte and bailey fortification. Historical records from O'Flanagan's 1933 survey mention a castle at this location, adding weight to the cartographic evidence.

The motte and bailey was a common type of medieval fortification brought to Ireland by the Anglo-Normans in the late 12th century. These structures typically consisted of a raised earthen mound (the motte) topped with a wooden or stone keep, accompanied by an enclosed courtyard (the bailey) at its base. The choice of location at the end of a ridge would have been strategic, providing natural defensive advantages and commanding views across the surrounding landscape.

Whilst no visible remains survive above ground today, the site's inclusion in the Archaeological Inventory of County Laois confirms its historical significance. The inventory, compiled by P. David Sweetman, Olive Alcock and Bernie Moran in 1995, documents hundreds of such sites across the county; many of them, like Moat Castle, existing now only as subtle earthworks or place names that hint at their medieval past.