Silia House (nprn 309634), situated on the west side of Presteigne, is noted for the historic interest of its late Victorian arboretum which still contains some fine specimens, particularly conifers, and for the early twentieth century woodland garden associated with Silia House. Silia also has historical associations with the Banks family of nearby Hergest Croft.which may have influenced some of the planting. 

The house, dating from 1906, is set on a level terrace, part way down the ornamental wooded hill side, facing south-east with views over a small park towards the town of Presteigne. The house is approached via a drive from the north, from an entrance and lodge, 'Silia Cottage' (309633), off Warden Road. The cottage is the earliest building on the site and was originally used as kennels for hounds, and the small, rudimentary parkland here was possibly used for exercising the dogs as well as providing a setting for the woodland. The lodge was the only building on the site in the later nineteenth century and the owner used the land to create a private arboretum, 'one of the finest in the kingdom with specimen trees of conifers, ornamental, deciduous and others'.
By the early twentieth century the cottage had become established as a lodge to a new house, Silia House, and the old kennels were used as vegetable stores before it became the gardener's residence with a large, lean-to peach house erected along its southern side (now gone). To the south of the cottage the ground slopes away steeply to a small pond.

The wood and the woodland garden surround the house to the north, west and south on south-sloping ground. Around the house there is a more formal area of garden including early twentieth-century shrub planting. The garden was created after 1906 with the introduction rare and expensive flowering shrubs and bulbs to be planted beneath trees of the arboretum and was probably established by the late 1920s. The drive and circulatory paths pass through this area. The four different ground levels are connected by sets of formal stone steps or rougher, more recent, timber ones. On the south of the house, the terraced drive is flanked by a strip of lawn along the southern edge separating it from a steep slope to the garden and park below. To the west, the garden becomes increasingly wooded with many mature ornamental trees including wellingtonia, cedar, spruce and tulip trees.

References have been found to various garden buildings, possible summer houses, in the woodland during the 1930s and 1940s and evidence has been found of a garden building within the garden. Links with Hergest Croft continued into the 1930s. The garden there is similarly laid out beneath an earlier arboretum by the Banks and dates from about 1896.

A small area of parkland was created between the southern garden/woodland boundary and the Slough road and town of Presteigne to the south and south-east but its early history is unclear. It is assumed that this land was bought, together with the woodland area and cottage in about 1860-70.

To the north-east, on the opposite side of Warden Road, lies The Warden earthwork castle (306465). The warden was landscaped in the nineteenth century as a public pleasure ground.

Sources:
Cadw 1999: Register of Parks and Gardens of Special Historic Interest in Wales, Powys, (ref: PGW (Po)49(POW)).
RCAHMW air photo: 965146/55.

RCAHMW, 12 July 2022