Built between 1847 and 1850 by local character Johnny Roche, the structure mimics a defensive fortress with its embattled parapets and turret-like towers, though it never served any military purpose. The building consists of a central three-storey rectangular block running northeast to southwest, flanked by semicircular tower projections that rise above the main parapet to form crenellated turrets complete with water spouts along their base.

The interior layout is surprisingly practical for what appears to be a folly castle. A central rectangular room measuring 4 metres by 2.1 metres is bookended by D-shaped chambers within the towers; one served as a workshop whilst the other housed a smithy, with stairs ascending through the northeast tower. Various window openings, both arched and lintelled, punctuate the walls, whilst an arched doorway provides entry through the northeast elevation. The structure’s purposeful design suggests Roche intended it as a functional workspace rather than mere architectural fancy.

Known locally as Roche’s Castle after its builder, the ruin bears a date plaque reading “1870”, though this was actually salvaged from another of Roche’s projects, a nearby bridge, and incorporated into the castle after his death. The castle stands adjacent to St Bernard’s Well and south of a corn mill, forming part of a cluster of historical features along this stretch of the Awbeg. Today, the roofless shell remains a curious landmark, its mock-medieval battlements slowly surrendering to time and weather whilst still managing to evoke the personality of its eccentric creator.