Llanfrechfa Grange was built in c.1843 to the design of J. H. Langdon as a residence for Charles Prothero, a member of a prominent Newport family. It is a two-storey nineteenth-century `Elizabethan?-style structure with attics, constructed of red brick with extensive Bath-stone dressings. The building's many gables are decorated with richly carved bargeboards under most of which are shallow, two-storey canted bay windows topped with cusped trellis balustrading. The other windows are mullion-and-transom crossed under simple hoodmoulds. The entrance is through an entrance porch with a `Tudobethan? doorway flanked by buttresses above which is a polygonal second storey with trellis balustrading and gable behind.

To the left of the entrance is an extensive addition in the same style, constructed in 1892 as attested by a prominent datestone, which also bears the initials of F. J. and Elizabeth Harcourt Mitchell, who purchased the house in 1860. In addition to this wing, the Mitchells also added the stuccoed polygonal chapel to the rear of the house which has coped steep gables and hoodmoulds over its two-light decorated windows. The windows contain stained-glass designs by William Wailes from the early 1860s, depicting scenes from the Life of Christ. There is further stained glass in the staircase window by Alfred Gerente of Paris (1857) depicting Sts Athanasius, Catharine and Alban which had been intended for All Saints Church, Margaret Street, London (Historic England Listing Number 1239569) but was removed by the architect William Butterfield as incompatible with his design. A conservatory, also added to the rear of the house, has since been demolished.

In 1953, Llanfrechfa Grange was transformed into a long-stay hospital for people with severe learning difficulties, with additional structures built in the surrounding grounds in order to accommodate patients? needs, including accommodation blocks known as `villas?. By the early 1960s, the hospital had more than five hundred beds, however with changing provision and standards for the treatment of severe learning difficulties in the second half of the twentieth century residence at the hospital declined, with the last residents departing in 2008.

Despite this change in use, some significant internal features survive, including the ribbed ceiling, panelling and Tudor-style stone fireplaces of the entrance hall, the fireplace to the left including carved panels which were bought in central Europe by the Mitchells. The former drawing room has a Jacobean-style plaster ceiling of c.1848 and walls decorated with full-height carved pilasters. The fireplace has a seventeenth-century timber overmantel with arcading and caryatids.

(Sources: Cadw Listed Building Description, Ref No 25494; John Newman, The Buildings of Wales; Gwent/Monmouthshire (Cardiff: University of Wales Press, 2000), pp. 301?302; `End of an Era for Llanfrechfa Grange?, South Wales Argus Online, 21.12.2008)
A.N. Coward, RCAHMW, 03.04.2019