Running across the joggled keystone, a joggled keystone being one cut in interlocking steps to distribute weight and resist being pushed out of position, are the words: "1614 John McNamara and / Onora Clanchi bilded / theis cheimneis in the / year of our Lord." The fireplace measures roughly three metres wide by two metres high, and the lettering fills the stone with the particular awkwardness of someone who misjudged the space. Letters are bundled together in places, and the phrase "in the" at the end of the third line had to be continued onto the adjacent stone, as though the mason, mid-chisel, realised the surface was running out.

The fireplace itself is thought to have originated not in Ballykilty House at all, but in Dangan Brack Castle, a separate structure in the same county. At some point in the eighteenth century it was apparently removed from that earlier building and reinserted into the kitchen of Ballykilty House, a practice that was not unusual in an era when useful or decorative stonework migrated freely between properties as buildings were demolished, altered, or absorbed. The McNamara name is well established in Clare's history, the family having held considerable power across the region through the medieval period, and the pairing of John McNamara and Onora Clanchi suggests the fireplace may have been commissioned to mark a union or to simply assert presence in a newly fitted-out space. What the inscription most honestly records, though, is the small human drama of a mason working in imperfect conditions, filling a surface by hand, and running slightly out of room.