Llywnywormwood park is located some 3km due south of Llandovery. It is notable for its historic interest as a late-eighteenth or early-nineteenth century landscaped park created out of rolling countryside with picturesque views across the parkland landscape and the countryside beyond. It is associated with the now-ruined mansion (nprn 17531) and nearby farmstead (403158). The estate was purchased by the Duchy of Cornwall in 2006.

The 62 acres or so of park and woodland occupy both sides of a small valley, which runs almost east to west, and through which the Nant Ydw/Nant Mydan meanders, forming an irregular plan but mostly north and south of Nant Mydan. The rolling parkland with scenic drives, picturesque lodges, bridges and lake is still embellished by careful, deliberate plantings. The dominant elements of the park - grass, wood and water - remain. Today the parkland is grazed, all the fences are temporary and the tree clumps remain. Although there has been much commercial planting, some planting of parkland trees has occurred. The Nant Ydw, an important element in this landscape, now flows into a marshy area of just over 3.5 acres which was once a lake, but the small island, dam and overflows are still discernible. Also extant are the bridges on the east and west sides of the park which carry drives over the Nant Ydw. To the west of the house site a small pond was created but long ago became silted.

The house was approached from the north, south and east. The north drive, off the Llandovery to Myddfai road, follows a circuitous line through the park. Originally views to the house may have been possible. There is an entrance lodge (North Lodge) and, part way along, an ornate lodge, Round Lodge, probably built as an eyecatcher from the house and which may have been visible across the lake. The east, Penhill, lodge has been much altered and the lodge on a track from the south-west is ruinous.

To the south-west of the house is a small walled garden (700106).

Sources:
Cadw 2002: Register of Parks and Gardens of Special Historic Interest in Wales, Carmarthenshire, Ceredigion and Pembrokeshire, 86, 89-90 (ref: PGW(Dy)71(CAM)).
Ordnance Survey 25-inch map, sheet Carmarthenshire XXVII.5 (1906 edition). 

RCAHMW, 22 April 2022