At Kilkea Demesne in County Kildare, four stone window mullions sit quietly in an arcaded area to the south-west of the castle, gathered there not by original construction but by deliberate collection. Mullions are the vertical stone dividers that separate the lights of a window, and these four represent fragments of architecture that might otherwise have been lost entirely to demolition or dispersal.

The person responsible for bringing them together was Lord Walter FitzGerald, a member of the Fitzgerald family long associated with Kilkea and a figure with a keen antiquarian interest in the monuments and remains of his estate. Rather than leave such pieces scattered or allow them to disappear, he assembled several monuments into a purpose-built arcaded setting, creating what amounts to a small lapidary collection in the open air. The four mullions are noted among these gathered fragments, though the precise buildings they originally belonged to are not recorded. The practice of consolidating architectural salvage in this way was not uncommon among nineteenth and early twentieth century landowners with antiquarian leanings, and it reflects a period when the preservation of historic material was often a matter of individual initiative rather than organised conservation.