1 CLIFTON TERRACE, MAIN ST., CASTLEROCK, Coleraine, Co Londonderry

1 Clifton Terrace is a late-Victorian three-storey single-bay blackstone end-terrace townhouse built in 1873, located on the south side of Main Street in Castlerock town centre. The building has been subdivided into apartments with resulting loss of historic detailing and changes to the internal floor plan. Despite these alterations, it retains important group value as part of the terrace, which preserves much of its late-Victorian character. Together with Babington Terrace to the east, it makes a significant contribution to Castlerock's architectural character.

The structure is built of uncoursed squared blackstone with a rectangular plan and a large three-storey return to the rear. The pitched natural slate roof features terracotta ridge tiles and a sand-lime chimney stack to the gable. Cast-iron ogee rainwater goods are carried on rubbed brick eaves with decorative black and yellow brick banding beneath.

The north-facing principal elevation has generally been altered to the ground floor left, where a bipartite window has been inserted. Upper floors retain a 1/1 window to the left. The right side features a 1/1 window above a two-storey canted bay with a leaded roof and moulded cornice over the window openings. Windows are predominantly replacement timber sash with horns in stepped painted brick surrounds and painted projecting sills; the canted bays have 2/2 sashes with painted surrounds and a continuous sill course. Second-floor windows have raised cambered heads with applied moulding to the jambs. The east gable displays irregularly arranged fenestration with three openings at each floor, including diminutive windows to the second floor left. The main entrance door at ground floor right is a raised-and-panelled four-panel timber door with panelled sidelights and etched glass panels, surmounted by a transom inscribed "1 CLIFTON TERRACE" and accessed via a single slab stone step.

Lined render appears at ground floor of the east elevation; the remainder has scratch coat finish. The east elevation contains a variety of irregularly arranged windows. At ground floor right stands a raised-and-fielded six-panel timber door with brass door knob. The south (rear) elevation is abutted at right by the large three-storey return, which has a two-storey gabled abutment to the west elevation with windows at first and ground floor levels. The west elevation is abutted by the adjoining building. Some uPVC windows have been inserted to the return and elsewhere.

The building is street-fronted and situated to the west of Babington Terrace in the centre of Castlerock. A communal yard to the rear is accessed via gravel alleys at the east and west of the terrace. The site is bounded to the south by the railway line, marked by modern metal fencing.

Castlerock developed following the opening of a railway halt in 1853 as a bathing resort on what had previously been open countryside. The area formed part of the Clothworker's Company estates and developed near Downhill House. The railway company actively promoted growth by offering cheap tickets to those who would build or buy villas. Sir Henry Bruce, the local landlord, took particular interest in Castlerock's development and required all new buildings to meet certain standards of quality and size.

The blackstone terrace of three buildings first appears in valuation records in 1873 as vacant houses leased from Joseph Connell, the likely developer. The first occupant noted was Mrs Linton, who occupied this house and number two from 1874. Initial valuation was £13, but rear additions made in 1875 raised the valuation to £14. In 1892, Jane Alcorn, a widow and grocer, took over this house and its neighbour. She was present at the 1911 census, living in the house alone at age 60. The property passed to Jane Duggan in 1921. In 1925, the valuation increased to £25 and 'shop' was added to the designation, indicating that although the premises likely operated commercially before this date, improvements occurred at this period, possibly including the circular treatment visible on the ground-floor window facade. The valuation dropped from £52 to £39 in 1962, with 'shop' deleted from the description; the ground-floor window surround was likely repainted at this time. Early 1930s valuation notes provide a plan showing rear extensions including a brick and corrugated iron motor house. The rooms comprised a shop, reception, kitchen and pantry, scullery, four bedrooms, bath and WC, and two attic bedrooms. The shop measured approximately 15 by 20 feet and operated only during the summer season. Subsequent tenants included Jane West (1928) and Miss E Maud Duggan (1946). The building was listed in 1977 when it had already been converted into four flats. Repairs and alterations occurred in 1984, and around 2005 the building was remodelled internally and extended.