Plas Machynlleth mansion house (nprn 29818) is located in a fine natural setting on the western edge of the town. An eighteenth-century house, it was restored by Sir John Edwards (former MP) before it became home to the marquesses of Londonderry, who owned extensive estates in the area. House and adjacent garden were later given to the town as a public park.

The house is set back off the Pentrerhedyn road behind a high stone wall on the north-west edge of a small park. The history of the Plas is intimately connected to that of nearby Llynlloedd (29510), a substantial farmhouse situated towards the south-east side of the park. The early history of the park area is unclear, but may date, as cleared ground, from the medieval period.
The earliest known record of the park occurs on a map of 1828 of the Machynlleth Estates. Land for the park was acquired from the 1790s to 1850, and from about 1840 Sir John Edwards set about creating a landscape park to provide the setting for his mansion and grounds. A number of fields around Llynlloedd farm were incorporated into the park and were planted variously with ornamental trees. The park’s drystone boundary wall can be traced for much of its length with entrances flanked by simple upright stone piers. Lodges were built at two of the entrances (410101 & 421007).

Level parkland rolls gently south from the garden boundary towards Llynlloedd. To the south of the park the ground rises and the wooded slope of Coed Llynlloedd forms a backdrop to the park. At the south-west end of the park the ground rises steeply to a ridge, with a number of small summits from which there are panoramic views. Since being given to the town, an area to the east of the garden of about 3 acres has been enclosed to make a rugby pitch and football field. In the north of the park, just to the north-west of the farm gates, a new housing development has been constructed on about 1 acre of ground.
Despite development and the loss of some planting and a summerhouse, much of the park and its backdrop of woodland remain. An ice house (43510) lies near the park boundary, to the south-east of the house.

The pleasure gardens were about four acres in extent and surrounded the house on the north-east, the east and the south, with further woodland in the south-west. The gardens remain in form, but much has been lost to redesign or redevelopment notably with the building of a leisure centre and carpark.

Sources:
Cadw 1995: Register of Parks and Gardens of Special Historic Interest in Wales, Powys (ref: PGW(Po)26).

RCAHMW, 5 July 2022