The site originally housed Ballygarran Castle, which by 1641 was described as a small castle owned by the Earl of Cork but occupied by one Catherine Power. This modest medieval stronghold commanded views across the river valley, taking advantage of the high ground some 100 metres north of the Blackwater’s waters.

The transformation of the site began around 1814 when R. E. Gumbleton started construction on a neo-Gothic house called Castlerichard, incorporating remnants of the earlier castle into its fabric. After Gumbleton’s death, his brother-in-law H. A. Bushe completed the project, resulting in a distinctive U-shaped residence that varied between one and two storeys. This architectural blend of medieval foundations and 19th-century Gothic Revival style created a unique country house that stood as a testament to both eras.

In 1930, the property took on a new spiritual purpose when it became home to a community of Cistercian nuns, who renamed it Glencairn Abbey. The sisters maintained the historic building until disaster struck in 1973, when a fire caused significant damage to the structure. Rather than abandon the site, the abbey was extensively rebuilt, allowing the religious community to continue their presence at this historically significant location where castle, country house, and convent have successively occupied the same commanding spot above the Blackwater.