Coming up from Carreg wen Fawr y Rugos on 1.5.2010, following the same route as Gladman, there are indeed a number of cairns. There are also lots of slabs and chunks of limestone scattered about, providing easy building material for megalithic structures.
I'm not sure which cairns I saw in relation to the OS map on the way up (comments on photos are somewhat guesswork based on Coflein and relative positions), one appears to have a dislodged capstone slab, but as you approach the giant Garn Caws there are two very prominent cairns.
The first, to the ENE of Garn Caws, is a grassy mound affair, about 4m across and situated nicely on the edge of the summit rise. The larger second, north of Garn Caws, is of stone block construction, situated somewhat unusually on a saddle rather than the most prominent point. It has been disturbed by walkers and/or antiquarians, but is still pretty large.
From here it's a very short stroll to the main summit cairn, Garn Caws.
Heading uphill from the Carreg wen Fawr y Rugos stone row (a general south westerly direction) it immediately becomes apparent that there is far more to this mountain than I first thought.....
We stumble across a large, circular, grassy cairn, which bears all the hallmarks of a Bronze Age burial site. Then another, followed by numerous further examples, culminating in a pair defining the final approach to the great summit cairn, Garn Caws. The western of this pair is a very substantial monument indeed, significantly not sited upon the summit of a prominent crag overlooking Dyffryn Crawnor, but upon its 'inner' shoulder, this rendering it invisible from the valley below. I would suggest this implies a specific relationship with Garn Caws, and a subservient one at that. [Coflein details of the various monuments within the cemetery are given as a miscellaneous post]
The locality of Pant Llwyd is liberally endowed with 'shake holes', those enigmatic circular depressions (I'm sorry, but 'holes' simply does not do justice to their exquisite natural symmetry) to be found upon the limestone uplands of South Wales. I must admit that, for all the world, they appear 'man made', or even of 'supernatural' origin. Could their existence have had a bearing on the location of the cairns? An intriguing thought, but one to ponder later on. For now, Garn Caws calls...
This desolate mountain bears the remains of several Bronze Age cairns of various descriptions and stature. According to Coflein:
1) PANT LLWYD, CAIRN I - SO12951700 - A dense stone pile 15m by 15m and 0.5m high, modern disturbance by walkers to create shelters.
2) PANT LLWYD ROUND CAIRN - SO13151734 - (Bronze Age Round Barrow) Located at the head of a minor stream valley, the ground falls away gently to the E and risES slightly to the W. The cairn consists of medium/large stones, turf consolidated, and measures 8m in diameter and 0.4m high. A number of large stones around the perimeter on the S and NE give the appearance of a kerb. At the centre of the cairn lies embedded a slab 1.5m long, aligned E-W, probably the remains of a cist.
3) PANT LLWYD ROUND CAIRN - SO13161742 - A very disturbed cairn of large stones consolidated with turf measures 8m in diameter and 0.4m high. At its centre lies a hollow with upcast piled up on its NE side. A large slab embedded in this position is probably the remains of a cist. There are traces of a possible kerb in the form of a number of upright and leaning slabs spaced around the cairn perimeter.
4) PANT LLWYD RING CAIRN - SO13231744 - Bronze Age - Located to the immediate SW of another round cairn, the site consists of a grassy ring bank averaging 1.5m wide and 0.1m high in which are embedded a number of short leaning and fallen slabs; at least 14 are visible, the most prominent lying on the W half of the cairn. The interior is turf covered but uneven and is marked by a low swelling, no more than 0.2m high, at centre. Overall the ring bank measures 9m (E-W) by 8m. There is a possible entrance gap on the SE.
5) PANT LLWYD ROUND CAIRN - SO13241744 - (Bronze Age Round Barrow). Located on a low hillock this cairn consists of a turf-consolidated pile of mainly large stones and measures 5m in diameter and 0.4m high. A shallow trench has been dug into the mound from its E side. A partially visible slab, aligned NW-SE, measuring 1.2m long embedded in one side of the trench and another of similar dimensions nearby are probably the remains of a cist. Its capstone is probably the slab which lies just beyond the mound on the SW and which measures 1.4m by 1m. Several leaning slabs and blocks around the S and W perimeter appear to be the remains of a kerb. A ring cairn lies to the immediate SW.
6) PANT LLWYD ROUND CAIRN (Bronze Age Round Barrow) - SO13121682 - a low mound of earthfast stones 4m in diameter and 0.4m high is located on a minor rise on an undulating hilltop. Possibly a sepulchral cairn though no structural features are apparent.