What appears to be a relatively modern structure from the 1820s actually conceals something far older within its walls; the remnants of a medieval tower house that once dominated this corner of the Irish landscape. The building's secret history becomes apparent when you examine its northeastern corner, where significantly thicker walls betray the presence of the original fortification.

The transformation of this ancient tower house into its current form came about through the work of Mr. Smith, an architect from Herefordshire, who remodelled the building in the 1820s. Rather than demolishing the old structure entirely, Smith incorporated the existing medieval walls into his new design, creating a fascinating blend of architectural periods. The corner tower and the eastern portion of the north wall retain their substantial medieval thickness, standing in marked contrast to the lighter construction of the Georgian additions.

This architectural palimpsest was first properly documented by historians Bassett in 1886 and Tempest in 1952, who recognised the significance of those tellingly thick walls. Their observations, along with more recent archaeological surveys conducted by the Stationery Office in Dublin during the 1980s and early 1990s, have helped piece together the building's layered history. Today, Barmeath stands as a testament to Ireland's pragmatic approach to architecture, where medieval fortifications evolved into Georgian residences, each generation building quite literally upon the foundations of the last.