Park, grounds and gardens associated with Dinefwr Castle, otherwise Newton House (NPRN 17603), essentially a mid seventeenth century and later mansion. The earlier house(s) on the site were located within Newton, a borough first mentioned in 1297 and which maintained some form of corporate life up to 1651. All traces of the borough were cleared when the present house was built in 1660-70 and a deer park established to the west. Contemporary oil paintings show the park as well as the ruined Dinefwr Castle crowning a wooded ridge to the south (425). The castle ruins are topped by a distinctive summerhouse. The house is surrounded by extensive formal gardens approached by an avenue from the direction of Llandeilo.
The mansion is set in rolling parkland just to the north-west of Llandeilo, on the north side of the river Towy. The park is approximately oval in shape and occupies some 970 acres with its height varying from about 30m AOD to 60m AOD. On the south boundary is the steep bluff above the Towy flood plain on which the medieval castle stands as a conspicuous feature in the landscape. To the west, north and east, substantial walls, completed c.1774, de-limit the area of the park; housing has masked and destroyed some of this boundary to the east.
Between 1750 and 1780 the eastern part of the present park was laid out as a naturalistic landscape and an engraving of the house in 1773 shows it in a parkland setting with no trace of the earlier formal gardens. The more picturesque landscape is to the west of the house, with the tree-covered, horse-shoe-shaped outcrops that make up the Rookery and the castle mound contrasting with areas of interspersed grassland. To the east the land has been moulded into gently rolling open land with the occasional clump of trees or individual specimens. There are fine deciduous trees within the park, some conifers to the south and more recent plantings in the centre of the park. There are notable clumps of beeches associated with Pen Lan-fach which form local landmarks. In the western half of the park is a small lake, used to rotate a turbine in the pumping house, the flow being controlled via sluices in the dam.
The main approach is from the east, off the A40 road, from an entrance to the south of which is East Lodge (17311). The drive winds gently above the river terrace until it sweeps to the east forecourt of the house. There was also a drive from the north side of the park, approaching via the King's Lodge, now on the opposite side of the A40. The drive crossed farmland and entered the park via a gated entrance. The south drive entered from Llandeilo bridge, passing in front of the South Lodge. It follows a north-west course to the house, traversing the escarpment above the river. A branch to the south leads to St Tyfi’s church at the wooded south edge of the park (114230). This small medieval church is built on, or near, the possible site of a Roman temple.
The house was reconfigured to its present surprising form in the mid nineteenth century with formal gardens enclosed by a ha-ha to the east and west (NPRN 23038). These are depicted on the Ordnance Survey County series 1st edition (Carmarthen. XXXIII.15 1886). The rear, western, garden features an elaborate fountain (NPRN 23037). There are various walled gardens to the south-west of the house.
The eighteenth century park engulfed Llandyfeisant (St Tyfi's) Church which acts as a picturesque feature within it. Other features of the park include an icehouse (401699), a deer slaughter house (31632) and a pump house for water supply (410648).
Source: Cadw 2002: Register of Parks and Gardens of Special Historic Interest in Wales, Carmarthenshire, Ceredigion and Pembrokeshire, 68-73 (ref: PGW(Dy)12(CAM)).
John Wiles, RCAHMW, 9 November 2007; additional notes David Leighton 7 February 2022.