12 Castle Place, Omagh, Co. Tyrone, BT78 5ER

12 Castle Place, Omagh is a two-storey stone building built in 1804, originally constructed as the gatehouse to the former County Gaol complex. It forms part of a group value listing with 7 Castle Place (HB11/09/004B) and is one of only a few surviving structures from the gaol complex, which was begun in the 1790s, opened in 1804, and closed in 1904.

The building is rectangular on plan, oriented south-facing, with a lower return to the east and a full-height addition to the north. It is constructed of dressed and squared sandstone built to courses, with a chamfered rendered plinth and dressed granite quoins. The hipped roof is finished in natural slate with lead ridge and hip caps. A dressed sandstone chimneystack with ovolo-moulded cap and beaded terracotta chimneypots rises from the roof. Ogee uPVC gutters sit on projecting eaves.

The principal south elevation is asymmetrical, featuring four bays. The most prominent element is a four-centred Tudor carriage arch to the left, which originally served as the main entrance to the gaol complex. This is surmounted by a window. To the right of the arch is a central square-headed painted timber door with a single fifteen-light door and nine-light overlight, surrounded by a painted stone architrave with keyblock. Above this is a single window. The right side of the elevation contains two further windows. All windows are square-headed painted timber 6/6 sashes with replacement glazing, set within painted stone architraves with keyblocks and sills.

The carriage arch features a painted chamfered stone surround on both the south and north elevations. The interior of the arch has a flat concrete ceiling and wrought-iron eyes in the intrados springing section. A stone bollard stands at the left of the south elevation. The arch interior contains two square-headed entrances with lugged sandstone architraves: the entrance to the right (formerly accessing 7 Castle Place) is blocked with red brick, and the entrance to the left (formerly accessing 12 Castle Place) is blocked with cement render.

The west elevation is entirely abutted by an adjoining structure, with only a section of the carriage arch exposed and detailed as described above. The rear north elevation is abutted at its left end by a two-storey addition. The exposed section of the original building contains a carriage arch to the right end, a single window at ground-floor level to the left end, and two windows at first-floor level. The addition is block-marked with cement-rendered quoins and features a blank north elevation. Its right cheek contains a single window to the left end and a single entrance also at the left end. This entrance is a square-headed replacement painted timber raised-and-fielded four-panelled door with white plate glass overlight, set within a cement-rendered architrave with keyblock.

The east elevation is abutted by a return structure, with only a blank section exposed. The return's east elevation has a single diminished 4/4 sash window at first-floor level to the left end, with the ground floor inaccessible and the right cheek inaccessible. The left cheek is blank.

The gatehouse stands at the southeast corner of the former gaol complex on an elevated site visible to the south of Abbey Street, spanning Castle Place. It is attached to the west by 7 Castle Place.

The plan, proportions, and ornamentation of the gatehouse all contribute to a stern and imposing composition that reflected the prison ideals of order and control. The carriage arch was the primary entrance to the complex and represents the most visible element to the public.

Historical records confirm the building's gaol function. The first edition Ordnance Survey map of 1833 shows it as part of the Gaol. The 1905-6 Ordnance Survey map captions the site as 'disused'. Lieutenant William Lacey's Ordnance Survey memoirs of 1834 describe the overall gaol establishment as consisting of old and new structures, with the former built in 1796 and used for women and debtors' prisoners, and the new part erected in 1823 in semicircular form with separate wards. Both were three storeys high and surrounded by a high stone wall. The establishment could accommodate 300 prisoners and was guarded by 14 keepers. Valuation Revisions record the property together with the County Gaol and yards, with the building recorded as vacant in 1909 and leased from Tyrone County Council. The valuation was £12 in 1912, when the occupier was William Porter. By 1913, the occupier was Joseph Ballantine. The gaol closed in 1904, and this gatehouse appears to be the former entrance to the older gaol, of which little else survives.

The building is situated within a conservation area. Alterations include the replacement of glazing in the sashes, uPVC gutters, cement render blocking of the internal arch entrances, and the addition of the northern block. These alterations detract from the original architectural character.