The farmstead of Penlanscubor is located along an early `top' boundary (NPRN: 406296) and is associated with a second farmstead known as Penlandoppa (NPRN: 405537). The first named mention of this farmstead dates to a lease of 1742 (National Library Wales (NLW): CW I, 823) when it was part of the extensive Crosswood (Trawsgoed) estate associated with the Vaughan family (later Earls of Lisburne). At the time of the 1766 survey of the Crosswood Estate it was still in use, and described as `House and Gardens', although by the time of the 1843 tithe it was no longer occupied, but depicted on the tithe map and thus seems likely to have been used as additional housing and storage by the farm of Troed-y-rhiw Issa (NPRN: 405540), which was then the main tenant farm of the area.

Prior to 1742 Penlanscubor appears to have been listed under the farmstead of Penlandoppa; in 1670, for example, Penlandoppa had two tenants, one paying £1, the other 12s (NLW: CW I, 398); by 1691 there was just one tenant, paying £1 and also 12s for `another pte of the same' or £1 12s `for two tenements called Penlandoppa' (NLW: CW I, 1147; CW V, 7, 8, 9). Whatever this farm's origins, it seems fairly clear that its name, which means `Penlan Barn', was coined in the early 18th century and may well refer to its subsidiary status at that time or might have referred to the big animal house (NPRN: 300571) situated close by.

The earthwork remains of the farmstead survive in relatively good condition and offers more evidence of chronological depth than the adjacent farmstead of Penlandoppa, although it shares similarities in that it comprises of two buildings and enclosures with a central passageway running through the middle of the farmstead. It is situated in a relatively sheltered spot at 288m OD, against the hillside, where an obvious cutting line along the base of the hill running south from the farm may be the result of quarrying for building material. The earthwork remains feature a well preserved rectangular building 13.4m long by 9.6m wide, with walls over 1m tall in places and an entrance at the northern end of its east wall. Joining this building is a large kidney shaped enclosure, its level interior created by terracing of the hillside, within which there are traces of cultivation furrows, resulting from an episode of ploughing. The entrance gap in the north bank of the enclosure seems to have been configured to facilitate the entry of livestock; we may assume that the ploughing traces represent a late episode in the history of this farm. The preservation of this structure and enclosure confirm the evidence shown on the 1766 survey and later tithe which suggest it continued in use well into the 19th century.

The 1766 survey and 1843 tithe also shows that a second building and enclosure was also in use at this period. These lie to the south and east of those described above, being divided by the central passageway running east-west through the farm. They are however not as well preserved as the other enclosure and building and may have fallen into disuse at an earlier date. There is also a clear discrepancy between the map depiction and the earthwork evidence. The 1766 plan and tithe show a similar kidney shaped enclosure with a building set within its northern edge; the field evidence, however, suggests a stand-alone oval enclosure perhaps of two phases, with an adjacent separate structure to the north, again possibly of two phases. On this interpretation the initial phase would feature a longhouse 12.5m long by 6.3m wide, most clearly defined by the line of its eastern wall, the remaining structure having been robbed out. The better-preserved building on the site described above is too small to have been a house and would therefore have originally functioned as a store, matching the arrangement we see at Penlandoppa (NPRN: 15220). To the south of this longhouse was a small sub-circular enclosure 14m in diameter. At a later date a 13m extension was added to the north eastern side of this enclosure, constructed out of earth but also faced with a series of orthostats in places. Whether this enclosure was divided into two parts is unclear; the division appears relatively denuded, which suggests that it went out of use. The extension of this enclosure blocked part of the longhouse, perhaps implying a reduction in its size and perhaps a change in function. The earthwork evidence suggests that the east end of the building may have been converted into an open sided shed or store of three bays, facing the interior of the farm. Considering the relative states of preservation of the two structures, it seems probable that the better preserved structure became the `house' (small cottage) mentioned in 1766.

A detailed survey of this farmstead was carried out by RCAHMW in 2006 as part of a wider study of the Troed y Rhiw area (NPRN: 405578).

Louise Barker, RCAHMW, March 2007.