Nannau is situated a few kilometres to the north-east of Dolgellau, high up on the west flank of Foel Offrwm mountain, above the north side of the Wnion valley. The present house, built in 1794-6 on an ancient site, is over 230m above sea level (nprn 28585). Whether the original, medieval, house was on the same site or within the adjacent deerpark is uncertain. Although probably medieval in origin, the core of the present park was likely laid out in the seventeenth century. It was then enlarged into a great 'romantic', designed landscape - much of which survives - in the late eighteenth and early nineteenth century, mostly by Sir Robert Williames Vaughan. This incorporated the deerpark (24514) and other pre-existing elements, and led to the present layout of the grounds, construction of drives, lodges, gates, arches and eyecatchers, and the planting of vast numbers of trees. The house, and adjacent home farm, lies towards the park’s north-east boundary.

The park is renowned for its extent and altitude. It is situated on a ridge between the rivers Mawddach and Wnion, on rocky and uneven terrain. When viewed from the south (the main approach) the rugged backdrop of mountains and forests provides a striking setting for the house. The entire designed landscape included the deerpark, tracts of woodland (including small areas of ancient woodland) and areas of open moorland as well as parkland in the sense of large, grazed enclosures dotted with planted specimen trees and some ancient trees. The original park was very extensive and undefined, blending into designed estate land and then natural landscape.

The park is now fragmented and not well preserved, remains are scattered and very variable and not all is included within the designated parkland area. Much of the deerpark wall is still intact (25414). The estate was once served by an extensive system of rides and drives some of which have fallen out of use, others surviving as forestry or farm tracks. Most are more-or-less unsurfaced, some now overgrown. The drive leading to the farm is also the main approach to the house. The main drive was formerly from the south, through Coed-y-moch, with a lodge, carriage arch and iron gates (28292). Another long drive approached through the deer park from the south-east, now mostly disused, with Deer Park Lodge (formerly Lower Lodge) at the entrance where the drive crosses the wall. Howel Sele Lodge (28513), formerly Upper Lodge, is also on this drive, set into the opposite wall of the deerpark, with an arched gateway and an iron gate alongside. A smaller area, immediately south-east of the house, is also named 'Deer Park' on the Ordnance Survey map of 1889. At this date it was well scattered with trees though it seems unlikely that it was originally part of the deer park; between the two is an area that may once have been a vineyard (‘Winllan’).

Also in the park, west of the house, is Llyn Cynwch around which is the circular Precipice Walk, and within the deer-park are fishponds and a ‘watch-tower’, probably a folly or eye-catcher possibly intervisible with a ‘summer house’ outside the park to the south. The presence of pillow mounds indicates rabbit farming (91389). Around the house are lawned pleasure grounds (700271); to the south an old kitchen garden (400837), and a later kitchen garden (700272). The woodland is mostly commercially managed forestry.

Sources:
Cadw 1998: Register of Parks and Gardens of Special Historic Interest in Wales: Conwy, Gwynedd & the Isle of Anglesey, 224-9 (ref: PGW(Gd)34(GWY)).
Ordnance Survey second edition 25-inch map: sheet Merionethshire XXXIII.11 (1901).

RCAHMW, 20 June 2022