Dunnamanagh Castle, East of 284 Berryhill Road, Donemana BT82 0PA

Dunnamanagh Castle is a ruinous late eighteenth-century country house in the Gothick style, located on the north side of Donemana village. It comprises the remains of a three-storey, three-bay structure built of random rubble stone bedded in lime mortar, with vestiges of lime render. The building retains three upstanding walls with a central full-height semi-circular entrance bay. A projecting ashlar string course delineates a loosely castellated parapet, terminated by stepped semi-circular projections at either side, which suggests a former concealed roof. There is no roof remaining, and nothing of the interior survives.

The principal elevation faces south and is four openings wide, arranged to either side of the semi-circular projecting entrance bay with loosely castellated rubble stone parapet. Windows are generally square-headed, with pointed-arched windows to the diminished second floor. Outer windows and those to the second floor are infilled with brick or rubble stone. To the extreme left, aprons separating windows have collapsed or been removed, leaving a single pointed-arched headed opening from ground floor sill level to second floor window head. The entrance bay has a single lancet opening to the upper level surmounting a former door opening, now of indeterminate profile. Chimney breasts are constructed in red imperial brick. The west elevation is blank, and the rear elevation is missing. The east elevation has two brick chimney breasts and the remains of a brick projection to the ground floor right, with the remains of what appears to be a bi-partite lancet opening. No sills remain to any windows.

The building has the appearance of a Georgian Gothick dwelling or folly and probably dates from the late eighteenth century. It is shown on McCrea and Knox's map of Tyrone dated 1813 as a castle in ruins. The later Ordnance Survey map of 1832 does not designate it as such, and it is not described as a ruin on Ordnance Survey maps until the third edition of 1905. The first edition Ordnance Survey map appears to caption it 'Earls Gift', but by the second edition it is named 'Dunnamanagh Castle'. The Townland Valuation of 1828–1840 lists 'an old castle' and tower, describing it as 'not habitable', although a valuation of £3 6s was assigned to it. In 1837, Lewis wrote that the greater part of this parish was granted by James I to Sir John Drummond, who founded the town of Dunnamanagh and built a bawn 109 feet square, no part of which remains; the bawn was removed some years previously and the modern building called the Castle was erected on its site.

The building's historical associations enhance its local significance. In a book of survey and distribution dating from 1666–1678, Downemanagh is listed as the property of Sir William Hamilton Esquire of Elston, Knight and Protestant. His descendant Sir John Hamilton is mentioned in late eighteenth-century correspondence between the Marquess of Abercorn and his agent James Hamilton as being in residence at Donemanagh or occasionally 'Earls Gift', and it may be that the residence referred to is the current building. James Hamilton's letters of 19 March 1793 and 19 March 1798 provide contemporary references to Sir John Hamilton's occupation of the house. He reported Sir John's death in 1802 and speculated that his son, 'Young Sir John', would be the last of the line. As far as can be determined from the correspondence, the son does not appear to have lived at Dunnamanagh, and the building may have begun to fall into disrepair shortly after Sir John's death. The stone used is local Dalradian schist and Tyrone carboniferous sandstone.

The castle is set in neatly maintained lawns belonging to adjacent late twentieth-century bungalows, which encroach closely on the structure. To the rear, the site drops steeply away and is bounded by hedges. Access is now via a gravel drive leading to the modern houses, which partially conceal the castle from the main road. Despite encroachment by late twentieth-century development, the scale of the castle ensures that it remains a landmark building in the village, prominently located on entry from the east. The building is too ruinous to be considered for listing.