Standing to the approx north west of.... and visible from.... the two great cairns crowning Pumlumon Cwmbiga, the trashed monument of Carnfachbugeilyn ['small cairn of the Bugeilyn', the lake visible below to the north] is always going to be an anti-climax. Nevertheless a visit is still worthwhile, if only for the superb northward views to Foel Fadian (also bearing a monument - actually monuments... one Bronze Age, the other to the late Wynford Vaughan-Thomas, the celebrated correspondent and walker) and Southern Snowdonia, not to mention the aforementioned Cwmbiga cairns crowning the retrospective horizon like a pair of (more than) ample... well, you know what.
As mentioned, the cairn is seriously disturbed - hey, so would you be if you had been messed around to such an extent - although still retaining a reasonable enough volume of material to be classed 'relatively substantial', particularly so if it had been located anywhere else than upon the wondrous Pumlumon. A boundary marker stone stands nearby.
Perhaps the salient point, though, is that the cairn lies on the route from Pumlumon Cwmbiga to the much more impressive Carn Fawr, visible to the approx west..... bonus site, then.
An indication of how the condition of upland Bronze Age cairns may be subject to considerable variation over relatively short time frames is perhaps given by the following Coflein entries:
1) 'A mutilated, summit-top cairn, 12.5m in diameter and 0.6m high. A shelter has been constructed on the NW side and a modern cairn on the S, a boundary stone, marking the county border, stands on the E side.....J.Wiles 16.04.02'
and...
2) 'A Bronze Age stone cairn, 9m in diameter and 0.8m high on a local summit. The cairn has been altered substantially. A small cairn on its southern edge contained evidence of structure and may be Bronze Age. A shelter had been hollowed out of the top of the cairn. When the feature was recorded in August 2006, most of the cairn was clear of vegetation although the exterior of it was covered in grass/heather.'
Bear in mind that the example upon Carnfachbugeilyn is not exactly easilly reached, either......[SN8263190380].