Farmstead consisting of a stone built farmhouse (NPRN 36111), an adjacent stone built store at the south-east corner and the remains of a large stone built range facing the farmhouse. The courtyard is enclosed by a further two stone walls.
The store at the south-east corner of the house appears to have originated as an oven- and bake-house, with a single rounded corner surviving. At the south-east corner of this structure is a chimney, which may have replaced the original chimney for the oven.
The larger range to the west appears externally to retain its original layout, with the north gable wall showing that it had a pitched roof similar to the main farmhouse. Internally however, the partition walls have been removed and replaced with blockwork walls. There is evidence of original openings to the north and west, but the windows do not survive in the same detail as those to the house, and there are ventilation slits, now blocked, indicating that it was ancillary to the house. S. Fielding, ref. CADW list description,01/02/2006 .
Additional note
Pen-Llwyn farm is an early to Mid-C19th planned farm, probably built by the Mostyn Estate and is almost identical in form & plan to the nearby Ffyddian farm (NPRN 404040) which has a refurbishment date-stone on its house inscribed '1912 M', the letter M representing the Mostyn Estate.
The stone-built structures are arranged around a walled yard with the house to south-east side and a barn/cow-house range to north-west side. There is also a loose-box or pig sty structure and bake-house along part of the south-west wall. The barn/cow-house range and house have dressed stone openings of similar material.
Although the barn/cow-house range has had its rear wall removed and roof replaced by modern, flat pitch, corrugated-iron, it retains considerable evidence of its original form. Further evidence of its original form are a series of early 1950 photos, which show two doorways at the cow-house end.
The barn part is approximately half the length of the range with central opposed doorways and flanking pairs of two-tier ventilation slits. The South-west gable-end has blocked openings for three 2-tier ventilation slits.
The cow-house had tethering facing the cross-walls, some cobble stones surviving against the barn's cross wall. The arrangement appears to have been an entry for cattle with flanking rows of cattle tethered facing the cross-walls (one removed). A further entrance in the north-east end bay may have been a stable, as there is a dressed stone window opening to the north-west side.
The house's outer bays (latterly domestic), formerly consisted of a cart-house with steps to granary over on the south-west end, while the north-east end was a stable with loft over. There is evidence for this in the structure, which is confirmed by the 1950s photos.

Visited, Geoff Ward, 15/02/2006, at the request of Peter Jones-Hughes, Conservation Officer, Flints.