Penmyarth is located above the north bank of the river Usk, at the north end of Glanusk Park into which it was integrated in 1831 (see nprn 700049). Its garden lies to the east and south of the house and is broadly laid out as mainly open, sweeping areas of lawn planted with trees and shrubs.

To the south-east the house looks out onto a wide circular lawn which is surrounded on the south and east by a stone ha-ha and on the north-east by a yew hedge separating the lawn from the forecourt. A paved terrace with columned veranda separates the front of the house from the lawn. A garden extension of shrub and wild ornamental planting is being developed in parkland along the east boundary of the garden beyond the ha-ha.

To the south and west of the circular lawn is a second, rectangular, lawn area raised above the east lawn and accessed from the house by a flight of steps. This lawn is partially enclosed by a high wall (a former walled garden). At the north end is the garden store/potting shed with a an ornamental dovecote, a former barn. Along the south side of the wall is a swimming pool on a raised, revetted, terrace 1.5m high, accessed by flights of steps.

The lawn below is ornamented by five circular rose beds arranged in a square with one central bed. This area of the garden is bounded on the south-east by a low retaining wall with a central rose arch at the top of steps. These lead down a grass slope to an early twentieth-century, oriental-style rock and concrete water garden of three pools linked by serpentine rills set in grass and amongst mature ornamental plantings, and with rockwork containing rough steps and seating areas on the western side.

To the west of the lawns is a third, large, garden area consisting of a lawn with ornamental tree and shrub plantings laid-out as an informal wild garden with mown paths and some modern sculptures. Just west of the garden wall gateway lies a brick and stone ornee ornamental cottage. To the north is a tennis court, a small orchard and a modern, ninteenth-century style greenhouse; to the west is an area of planted woodland and Penmyarth (estate) Cottages. The north boundary here is the park wall.

Sources:
Cadw 1999: Register of Parks and Gardens of Special Historic Interest in Wales, Powys, 88-95 (ref: PGW (Po)3(POW)).

RCAHMW, 2 March 2022