Plas Machen, a house dating back to the sixteenth century (nprn 20669), lies above the north bank of the Afon Rhymni at Lower Machen on the edge of a scarp overlooking the river valley. The garden is an integrated Tudor layout of terracing, walls and fishpond. It lies to the south and east of the house.

To the east is a levelled grass forecourt bounded by a Tudor wall on the south and later, low walling on the north. The main area of gardens is to the south where massive stone retaining walls contain a series of terraces, long axes north-west by south-east, now grassed over. There are two main walled compartments divided by a high stone wall, each with two terraces with steep scarps between them. The upper one (walled but with some gaps), has a narrow terrace at the top and a wide, gently sloping one below. In the lower compartment the upper terrace is narrower than the lower. At the north-west end of the upper terrace is a stone wall with a doorway into the forecourt.

The terraces overlook the Rhymney valley to the south and immediately below them is a rectangular level area with a narrow rectangular fishpond along its west side. Although probably likely utilitarian, it appears to have been deliberately incorporated into the overall scheme of the garden: it is the exact length of the terraces and is aligned with them. Only the lower compartment is now in use as a garden; the upper one and the area below, bounded by the fishpond, is permanent pasture.

Sources:
Cadw 1994: Register of Parks and Gardens of Special Historic Interest in Wales: Gwent, 6-7 (ref: PGW (Gt)55(MON)).
Ordnance Survey, six-inch map: Monmouthshire XXXIII.1 (third edition 1916).

RCAHMW, 14 June 2022