Bertholey House, a ruined Regency house with origins in the sixteenth century (nprn 36462), is located in a rolling landscape on the east side of the Usk valley, to the south of Llantrisant. It is set roughly centrally within a park, landscaped during the first 30 years of the nineteenth century. The park is small but was extended to 393 hectares in 1895. It is bounded by public roads on the west, by woodland on the south and east, and elsewhere by farmland.

From the house views extend over the park to the west and across the Usk valley. The park consists largely of rolling pasture with isolated deciduous trees and a few clumps (mainly deciduous, some Scots pines). The old drive, now a stony track, runs from the west at the old A449 road where there is a lodge at the entrance (36463), winding up to the house through the park. The modern road runs between the entrance and the house. The main area of woodland in the park is Garden Wood to the north of the house, an unmanaged woodland of mainly deciduous trees, interspersed with yews. It was landscaped with winding walks, ponds and planting, but much of what is known to have existed has now gone.

A dovecot east of the house is stone-built, cruciform in shape, with single-storey 'transepts' and a two-storey centre. Now disused, part may have been used for poultry.

Gardens lie around the house, with a kitchen garden to its north-east (265989; 700404).

Sources:
Cadw 1994: Register of Parks and Gardens of Special Historic Interest in Wales: Gwent, 16-18 (ref: PGW (Gt)11(MON)).
RCAHMW air photos: 94-CS 0414-5; 945057/55; 945058/56-7

RCAHMW, 5 September 2022