Gwydir is sited on the edge of the flood plain of the River Conwy, at the foot of a rocky crag, just over the river from Llanrwst . It is notable for the partial survival of its sixteenth-century garden, including walls and gateways, around a contemporary unit-system house (nprn 26555), with later features of interest including a pool with fountain, a yew avenue and box parterre, with an exceptional, possibly early seventeenth-century complex of summer house, viewing mount and bowling green at Gwydir Uchaf (26556). There is a history of development and change from the sixteenth to the nineteenth centuries. The estate is notable for having been owned and occupied by several generations of the Wynn family, and in the seventeenth century the gardens were known to have been of some sophistication.Gwydir was also visited, and written about, by Thomas Pennant, the noted eighteenth-century antiquary and tourist.

The pleasure grounds are in two parts: the main gardens around the castle; and an area around Gwydir Uchaf, behind the house (across the B5106), which includes a path known as Lady Mary's Walk (86387).

The main gardens are laid out with trees, walks, a terrace, an avenue of clipped yews and a fountain, all spreading to the north, west and south-east of the castle. The house is approached from the south-west, off the B5106 to which it is adjacent. The long, low, narrow terrace (‘Great Terrace’) runs along the north-eastern side of the house, terminating in an ornamented archway at its north-west end (309166). The terrace is bounded by a laurel hedge with steps down to a rectangular area of possible sixteenth-century origin. Now grass with shrubs and a large old Yew, it used to be laid out with a pattern of beds and borders. It is bounded on the north-west by early garden walling, the north-east side open to view.
South-east of the house is the large, roughly square walled courtyard with a gatehouse in the west  corner. The surrounding walls are about 1.5m high, with slate coping and trefoil finials, possibly taken from the older wall which it replaced when the courtyard was enlarged in the early nineteenth century. The south-east gateway is Tudor in date. A simple gateway in the north-east wall accesses the terrace. The otherwise gravel interior is occupied by a large circular box parterre representing a Tudor rose in eight open segments. Shrub borders fill the east and south corners.   
To the north-west of the house is a large, gently sloping lawn with a long avenue of yews aligned on the house front. A massive slate seat across the north-western end of the avenue is set in a paved area with box bushes behind. Part way down the avenue is an octagonal pool in Victorian Romantic style but which may have sixteenth or seventeenth century origins. A central island supports a fountain. The pool is fed by a stream culverted from surrounding hillsides. Circuit walks round the garden, with linking paths, are now mostly out of use and grassed over. In the south-east survives a remnant path which appears to have been originally planted with trees and shrubs.
The garden south of the house is informal, planted with specimen trees and shrubs. A tree-planted area at the extreme southern end, the ‘Royal’ and ‘Statesmen’s’ Gardens, were ceremonially planted at the turn of the nineteenth century by visiting dignitaries. Several very large trees grow in the carpark area. The walls along the road boundary are probably nineteenth-century in origin. There are several gateways through the road walls, and one (disused) onto the Llanrwst road near the north corner of the garden.

The garden is bounded on the north-east by a ha-ha, probably early nineteenth-century in date, which runs from the Llanrwst road right round back to the Betws-y-Coed road (B5106) south of the house. All the area between the ha-ha and the river is shown as parkland on early maps. Originally enclosed in 1597, it would have formed the main aspect from the house and garden. It is now given over to farming, having lost most of its specimen trees aside from some old boundary trees. A narrow stone causeway crossing the former parkland, from the parking area to a quay on the River Conwy to the east, may have been used for bringing up supplies from the river, and may also have had a function in flood prevention; in the nineteenth century it was known as the 'Chinese Walk'. 

Gwydir is associated with Parc Mawr, a sixteenth-century deer park, on higher ground south of the castle, on the opposite side of the B5106 (700063). 

Sources:
Cadw 1998: Register of Parks and Gardens of Special Historic Interest in Wales: Conwy, Gwynedd & the Isle of Anglesey, (ref: PGW(Gd)4(CON)).
Ordnance Survey second-edition 25-inch map: sheet Denbighshire XVI.1 (c.1900).

RCAHMW, 24 March 2022