Trevalyn House (nprn 27959) is located in the Alyn valley, south of the village of Rossett. It is notable for the survival of its nineteenth-century pleasure grounds which include a substantial rockery and informal woodland with some fine mature trees, both coniferous and deciduous, and for its well-preserved Victorian kitchen garden walls. 

The house was built in 1754 but the landscaping visible today dates from the nineteenth century when the estate was occupied by the Townsend family; the grounds may have been enlarged to the north at this time. Although little is known about the history of the gardens some of the specimen trees must have been planted in the eighteenth century, probably when the house was built. For several decades in the post-war period the house was used as a hospital and various extensions have encroached upon gardens on the west side of the house; an elaborate formal garden to the west of the house, which included a conservatory and a pergola, has been lost.

The pleasure grounds and kitchen garden occupy a rectangular area around the house, the kitchen garden on its east side. The house and grounds were approached from the main entrance and lodge in the north-east corner, off Manor Lane. The entrance is flanked by dressed stone walls and rusticated piers, the lodge on the north side. The drive runs westwards to curve south towards the south front of the house. A back drive, also off Manor Lane, runs along the east side of the house to join the main drive south of the house. A further approach from Cox Lane, with a lodge (now demolished), on the south boundary of the grounds, is now disused.

The layout of the grounds is largely informal woodland and lawn with more formal areas to the south and west of the house. The main drive, lined with oak trees, runs through an area of rough grass flanked either side by belts of trees, including some large conifers. A broader belt of woodland down the west boundary is dominated by mixed mature deciduous trees with an understorey of ornamental shrubs.

To the south of the house is a lawn bounded on the south by a straight ha-ha which affords views from the garden out across the unornamented fields beyond. A wide gravel path leads from the centre of the house to the ha-ha, with stone steps up the parapet wall. East and south-east of the house, towards the east boundary, are some large specimen conifers and a belt of mixed woodland.

Photographs from the 1880s show that the garden north-west of the house was a highly elaborate formal garden of island beds with raised stone edgings; these have all completely gone. But west of the extension to the former hospital is a large rockery, already in place in the 1880s. It consists of mounds of rockwork with narrow winding paths edged with boulders between them. The rockery is planted with mixed ornamental trees, including copper beech, ginkgo and dwarf conifers.

In a grassy area west of the new hospital wing, near the drive, is a twentieth-century feature consisting of an octagonal concrete pillar set in a central raised area of limestone rocks backed on the west by an arc of  yew hedging. A formal, geometric layout of paths and plant beds in a square area on the south front of the extension, is also a recent feature.

North-east of the house lies the kitchen garden (700071). 

Sources:
Cadw 1995: Register of Parks and Gardens of Special Historic Interest in Wales, Clwyd, 256-9 (ref: PGW(C)74(WRE)).
First-edition Ordnance Survey 25-inch map: Denbighshire XXII.9 (1871).
RCAHMW air photos: 94-CS 1532-5; 945165/44-5
Additional notes: D.K.Leighton

RCAHMW, 1 April 2022