Gardens on the property of Great Harmeston House (formerly 'Big Harmeston', nprn 22008), located to the north of Milford Haven, accessed from the south side of the A4076. Little documentation remains relating to the early history of the property. It is known that it was called 'Hermaston' in the sixteenth-century and that Thomas Jones of Hermaston was sheriff in 1589.

Although mapped evidence shows that the area occupied by the garden altered somewhat between c.1840 and 1908, the garden areas today are very similar to those shown in 1908, the main area of interest being the enclosed area to the south of the property. The garden orchard is a rectangular area of about half an acre enclosed by a wall to the north, earthen banks to the west and east and the railway line to the south. The area is now one of rough grass, brambles and the vestiges of an orchard. In the north-east corner is a small, almost square garden ruin, possibly a grotto, objects of some beauty or importance being housed in the niches within it. Alternatively it was an arbour, the niches serving as seats.
To the south are two garden mounts, each about 8m diameter, which terminate the earthen banks immediately prior to a tiny lake or pond, all of c.1800 or earlier. An almost circular level area with a diameter of about 4.5m immediately to the south-west of the western mount and overlooking the western side of the small lake, may have been the site of a summer house.

Sources:
Cadw 2007: Register of Parks and Gardens of Special Historic Interest, additional and revised entries part 1, ref: PGW(Dy)19(PEM).
Ordnance Survey County Series 25-inch plan: sheet Pembrokeshire XXXIII.7, editions of 1876 & 1908.

RCAHMW, 11 October 2017