High Glanau is located on the western edge of the high plateau to the west of the Wye valley, about 2km north of Trellech. It was the last home of H.Avray Tipping (1855-1933), architectural historian and garden designer, who lived there from 1922 onwards. The house was designed in an Arts-and-Crafts/ vernacular style, and is surrounded by a landscape laid out as a complex of woodland and open gardens, between 1922 and 1929.

The main entrance is off the B4293, to the north of the house, the drive winding through woodland to a small forecourt on its east side. The gardens lie mainly to the north, west and south of the house on high ground sloping to the west. They fall into three distinct areas: the formal terraces around the house (nprn 37035); the woodland garden to the north of the house, and the lower woodland garden in the steep-sided valley to the west. But the extensive planting of shrubs and herbaceous plants throughout all parts has almost entirely disappeared.

To the south of the house is a small paved terrace built out over the slope, below which is a long rectangular terrace of lawn flanked by flower beds and bounded by a wall (east) and hedge (west), grass areas flanking each side. At the far south end is a pergola on stone piers set against the boundary wall of the kitchen garden beyond (37038).

On the west two stone-revetted terraces with plant borders, linked by central stone steps flanked by square stone piers, run the length of the house. The steps continue down the steep grass slope below the terraces to a paved area centrally set with an octagonal pool and fountain. To the north-west is an oblong lily pool located above the lower 'wild' garden on the west. This is an area of semi-natural deciduous woodland in a small, steep-sided, north-south stream valley. On its east side a number of winding paths were made. Dense plantings along their edges with shade and moisture loving plants have now gone but the trees and the paths remain. The stream was dammed in places, a still-functioning hydraulic ram installed to lift water to a reservoir to the east of the house, used for the pools in the garden.

To the north of the house a west-sloping area of semi-natural deciduous woodland was converted into a naturalistic wild garden and glades with winding paths bordered by plantings of semi-shade loving plants; although now gone the trees and paths remain. Paths connect to the drive and the area of the octagonal pool. To the south of the pool is a smaller similar area, now overgrown. Near the house is the Gardener's Cottage (37036). 

Sources:
Cadw 1994: Register of Parks and Gardens of Special Historic Interest in Wales: Gwent, 48-50 (ref: PGW (Gt)45(MON)).
https://ngs.org.uk/view-garden/19406/ National Garden Scheme photo gallery: High Glannau.
RCAHMW air photos: 965071/54-5.

RCAHMW, 10 June 2022