The ruins of Llwyn-y-Wormwood are situated overlooking parkland to the north and are believed to have been part of the Williams Estate from the C17th. A David Williams of LLwyn y Wormwood is recorded as being buried at Myddfai on 1st July 1720. Visitors to the estate included Richard Fenton in 1809, who commented Llwyn y wermwd, a charming situation, ground very parkish, ornamented with fine masses of old wood. The present building dates mostly from the time of George Griffaes-Williams who inherited the estate in 1785 and set about creating a fine mansion. He was created a Baronet in 1815.
The building is a late-C18th and early C19th, stone-built, 2 ?-storey, block consisting of three north-south rectangular units attached to a rear east-west range (see sketch plan). A number of additions to the west end, which have collapsed, are shown on the OS map first edition. The surviving walls are mostly well built of local coursed stone. There are flat stone arches to openings and well cut long & short quoins to corners and chimneys. Some late-C18th/early-C19th iron fireplaces remain with decorated side panels and bar grills.
The existing 3-bay north facade has gable-ends flanking the remnants of a central canted bay. At the rear an earlier east-west range formerly linked them together, although only the west gable-end survives slightly set in. Other walls abut this gable-end indicating it is earlier. The projecting part of the west elevation has doorways on ground-floor to former services lean-tos (as shown on the OS map). These adjoined the now detached bake-house range to west. Most of the east and south elevations have collapsed and been removed.
Evidence on the ground and a sketch from the north-east of 1888 indicate there were two projecting bays to the east facade, one canted and the other semi-circular, although now, only some footings of this facade remain. The sketch shows a viewing tower to centre at rear. It shows a chimney to the rear unit's gable-ended east-elevation, which has flanking circular openings or recesses above the semi-circular bay. There is a similar existing, central single recess, at the north elevations western gable-end.

Bake-house range.
This stone-built, 5-bay, single-storey range, aligned north-south, was used as services for the mansion immediately to the east. The 3-bay part of it is possibly C17th, with deep fireplace and ovens. It was later extended into the bank, for a further 2-bays. All the roof-trusses are pegged with lap-joints at apex, lap-collar and tie-beam of late-C18th/early-C19th type. The roof has been repaired with two pairs of trenched side-purlins and a vertical ridge-piece. Two large openings for tractor entries in the side walls were made, when it was used in the C20th for cattle housing (see existing racks and manger in side walls). However the original openings can be interpreted as each having had a window and doorway (see sketch plan).
The 3-bay unit has an arched timber lintel to fireplace and two bread ovens set into each corner. It is assumed to have had a cross partition alongside a former doorway dividing the room.
The other doorway, blocked in brick, once provided access to a room with loft over and two windows facing north, perhaps a dairy.
The later 2-bay unit to the south may have been a wash-house with narrow larder beyond the partition and separate gable-end doorway.
Visited, Geoff Ward, 02/06/2005, as part of the Tir Gofal project.

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