By 1619, when surveyor Pynnar conducted his inspection of Ulster plantations, the site boasted an impressive three-storey castle complete with a defensive bawn and two flanking towers; a formidable structure that represented the new Protestant ascendancy in this part of Ireland. The castle’s strategic importance and solid construction seemed to guarantee its permanence in the Cavan landscape.

However, the fortunes of medieval fortifications were often unpredictable, and this castle met its end not through siege or rebellion, but through an accidental fire that completely destroyed the structure. In 1764, G. Mountgomery Esq. built a new house on the castle’s foundations, creating what became known as Ballyconnell House. This Georgian residence represented a shift from the defensive architecture of the plantation period to the more comfortable country houses favoured by the landed gentry of the 18th century.

Archaeological investigations in 2004 uncovered tantalising remnants of the site’s earlier history. During pre-development testing, archaeologists discovered a substantial wall measuring 10 metres in length and up to 0.7 metres in height, with a width of one metre. The wall’s well-coursed stone construction, bonded with white lime mortar, hints at the quality of the original castle’s masonry and provides a physical link to those early plantation days when Captain Culme and Walter Talbot first established their foothold in this corner of Cavan.