They are the salvaged remains of an earlier building: three chamfered sills from two-light windows, two chamfered window jambs, and all of them bearing the small rectangular sinkings that once held iron bars. Chamfering, the angling of a stone edge to remove its sharp corner, was a common feature of medieval and early modern Irish tower houses, and these pieces are almost certainly all that survives of the original fenestration of the castle before nineteenth-century renovators replaced the windows with ogee-headed brickwork.

The site's history is considerably longer and more turbulent than the modest ruin now suggests. A castle at Dun Loich was built in 1215 by Maurice FitzGerald, but after the Geraldines were defeated at the battle of Callan in 1261, the MacCarthys demolished and burned it. It was refortified, only to be abandoned again in 1280 when its guards fled in fear of MacCarthy forces and burned it as they left. The surviving tower house is associated with the O'Sullivan Mores, a later occupancy that itself endured demolition by the Earl of Ormond in 1570, reoccupation, and eventual forfeiture in 1656. Sir William Petty, the surveyor and economist who mapped much of Ireland under the Down Survey, acquired it after that forfeiture. By the late 1600s it had passed to the O'Mahony family, one of whom undertook substantial renovations in the 1820s, rebuilding the east wall, inserting the pointed southern doorway, and replacing most of the original windows. Thomas Johnson Westropp sketched the renovated structure in 1891, and that drawing survives in the Royal Irish Academy. The tower house now stands in the grounds of the Dunloe Hotel on an elevated ridge overlooking a bend of the River Laune, its upper floors inaccessible, its timber floors and wall-shutterings still just visible within the shell. The limestone fragments on the steps are, in a sense, the only legible remnant of what the building looked like before all that remaking began.