The house at Derwydd, Llandybie (nprn 17296), is located on a south to south-west facing slope of one of the small valleys made by the Afon Marlais. Immediately around the house is gently undulating farmland, but to the south the limestone ridge of Pentre Gwenlais rises steeply and, to the east, Black Mountain (Mynydd Du) rises from the Cennen and Loughor valleys. The house is surrounded by gardens in a setting that once had some parkland character. Although the site is an ancient one the pleasure grounds around the house were laid out in the nineteenth century.

The garden is bounded on three sides by a stone wall that rises to 3m at its maximum. The wall to the north partially runs alongside the south wall of the walled garden (700230). On the west and south the wall follows the course of the road as it descends towards the ford on the south-west. The main drive is off the Derwydd Road to the west front, a spur leads off to the south towards the service area, while a branch to the north arrives at the west front of an extension to the mansion. Either side of the main drive are plantings of woody exotics, giving way to more shrubby, flowering species and formal flower beds nearer the house. The creation of the present layout involved a substantial terracing operation to the east & south-east of the house. An earlier terraced garden, now occupied by the walled garden, survives only as a narrow grassy terrace with topiary and vestiges of herbaceous border between walled garden and the house.

The garden can be divided into several distinct areas. The area to the front (west) of the house and to the north of the upper drive is essentially a pleasure garden. To the north of the upper drive is the orchard. To the east of the orchard and to the north of the house is the walled garden. North-east of the house are the woodland walks and `painting' lawn. The woodland area was created 1887-1906, and includes a Gorsedd circle, and ornamental plantings at its north and east extents. Within the grass faint traces of flower beds or borders are visible with some horticultural survivors. To the south and east of the house is a lawned area embellished with topiary, and includes a croquet lawn, a decorative well and bamboo clumps. Intermittently on the terrace and lawn areas are examples of topiary. At the base of the lower terrace wall is a small rill and a kidney shaped pond.

During terrace landscaping work in 1888 purported finds of Roman date implied the presence of a villa site in the vicinity (402704).  

Sources:
Cadw 2002: Register of Parks and Gardens of Special Historic Interest in Wales, Carmarthenshire, Ceredigion and Pembrokeshire, 8-12 (ref: PGW(Dy)6(CAM)).
Ordnance Survey County Series 25-inch plan: sheet Carmarthenshire XLI.11 (editions of 1876 & 1906).

RCAHMW, 8 June 2022