Ancient Monuments

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Penllergaer orchideous house

A Scheduled Monument in Penllergaer (Penlle'r-gaer), Swansea (Abertawe)

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Latitude: 51.6711 / 51°40'15"N

Longitude: -3.991 / 3°59'27"W

OS Eastings: 262416

OS Northings: 198797

OS Grid: SS624987

Mapcode National: GBR GX.7RCY

Mapcode Global: VH4K2.R8Z9

Entry Name: Penllergaer orchideous house

Scheduled Date: 12 December 2007

Source: Cadw

Source ID: 4350

Cadw Legacy ID: GM596

Schedule Class: Civil

Category: Garden building

Period: Post Medieval/Modern

County: Swansea (Abertawe)

Community: Penllergaer (Penlle'r-gaer)

Built-Up Area: Gorseinon

Traditional County: Glamorgan


The orchideous house is a small, rectangular, ruined glasshouse (9 x 4 m) situated centrally within the walled kitchen garden of Penllergare, to the north-north-east of the central circular pool. The building is without its superstructure but its walls, although ruinous, appear to stand more or less to their full height. The interior structural fittings appear to be partially preserved but much decayed and tumbled. Immediately to its east are the remains of the coal pit and structures associated with the fireplace and boiler that enabled hot water to be cascaded into the glasshouse. Beside the building are traces of paths.

The orchideous house was built by John Dillwyn Llewelyn in two phases. In 1835 he built a more straightforward glasshouse for orchids on the site but in 1843 redesigned it to provide a more specialised environment. This was to be an epiphyte house for non-terrestrial orchids. His idea was to recreate a tropical environment, as far as was possible, based on the Essequibo rapids, where one of the orchids he wanted to grow, Huntleya violacea, lived. Above a central pool warm water splashed down a series of rocky ledges, evaporating on the way to create a hot, steamy atmosphere. Contemporary accounts indicate that the orchids flourished and that visitors were amazed by their success.

There are contemporary illustrations of the interior, including an engraving in the Gardeners Magazine (1876) and a watercolour by George Delamot (about 1846). These show the waterfall and pool, plants on the side benches and plants slung from the low-pitched glazed roof. A plan and elevation drawings, dating to the mid 1850s, is very useful in that it not only shows the layout in detail but labels every feature.

The mechanics of how the water was brought to the house, heated and fed into the building are only sketchily known. Water was brought from a pond on the Home Farm on higher ground to the west of the park. The pipe carrying water to the top of the cascade ran in a single coil through the boiler, thus heating the water. Hot pipes also ran around the inside of the walls.

The cascade was built of flat cut rocks, some of considerable size, from the Penllergare quarry. These may still be on site, hidden by undergrowth, but are no longer in situ.

In the 1890s John Talbot Llewelyn converted the glasshouse to a camellia house. It is not clear whether this involved any structural changes to the interior.

The monument is of national importance as a very early and very rare example of its type. This was in fact the first orchideous house in Britain where an attempt was made to recreate a tropical atmosphere. The attempt was by all accounts successful and the orchideous house was much visited and praised by horticulturalists and orchid growers at the time.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.

Source: Cadw

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