Built around 1650 by the Gore family, who arrived in Ireland as part of the Cromwellian settlement, the castle replaced an earlier O’Hart stronghold that had commanded this strategic position overlooking Drumcliff Bay. The Gores, originally from Derbyshire, quickly established themselves as prominent landowners in the region, with Castle Ardtermon serving as their primary residence for nearly two centuries.

The castle’s architecture reflects the turbulent times in which it was constructed; thick walls, narrow windows, and defensive features speak to an era when comfort took second place to security. Despite its fortress-like appearance, the interior once housed elegant rooms with ornate plasterwork and carved fireplaces, remnants of which can still be glimpsed today. The Gore family’s influence extended well beyond the castle walls, with Sir Ralph Gore serving as Speaker of the Irish House of Commons in the early 18th century, whilst his descendants continued to play significant roles in local politics and society.

By the mid-19th century, the Gore family had relocated to nearby Lissadell House, leaving Castle Ardtermon to gradually fall into disrepair. Today, the castle stands roofless but remarkably intact, its ivy-covered walls and empty window frames creating an evocative silhouette against the Sligo landscape. Local folklore has woven itself around the ruins, with tales of hidden treasure and ghostly apparitions adding to its mystique. The site remains accessible to visitors willing to trek across the fields, offering a tangible connection to Ireland’s complex colonial past and the families who shaped the cultural landscape of County Sligo.