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East Fforest Fawr and Mynydd-y-glôg
Historic Landscape
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Historic Landscape Characterisation

East Fforest Fawr and Mynydd-y-glôg: Cefn Cadlan – Cefn Sychbant – Mynydd-y-glog
Hirwaun community, Rhondda Cynon Taff
(HLCA 1199)

CPAT PHOTO 2509-32

Extensive moorland area with important traces of prehistoric settlement, land use and burial together with a scattering of post-medieval and recent sheepfolds and small disused quarries and associated limekilns.

Environmental and historical background

Extensive area of just under 1,800 hectares of mostly unenclosed moorland generally above 300 metres above sea level which topographically can be broken down into three upland blocks which gradually diminish in height to the south. To the north is the roughly east-west ridge of Cefn Cadlan which rises to a height of 480 metres and is drained to the north by streams running westwards to join the Afon Hepste and eastwards to the Garwnant and other tributaries of the Taf Fawr. To the south is a shallow col with streams running westwards to join the Nant Cadlan and eastwards to join the Nant Aber-nant and other tributaries again of the Taf Fawr beyond which is the east-west ridge of Cefn Sychbant which rises to just under 420 metres. At the southern end of the area is the plateau of Mynydd-y-glog which rises to about 390 metres beyond which streams drain southwards to join the Afon Cynon. Mynydd-y-glog is separated from Cefn Sychbant by another shallow col occupied by streams running westwards to join the Nant Cadlan and eastwards to the Nant Sychbant and again other tributaries of the Taf Fawr.

The area is crossed by a band of Old Red Sandstone running across Cefn Sychbant, to the south of which is a band of Carboniferous Limestone on Mynydd-y-glog, with sandstone and millstone grit forming the predominant solid geology of the southern end of the area. Soils mostly overlying Old Red Sandstone or sandstone drift deposits, predominantly seasonally waterlogged and acidic, with a peaty surface horizon. They supporting wet moorland of poor grazing quality with towards the west smaller areas of better-drained land overlying sandstone and limestone in the Cefn Cadlan and Mynydd-y-glog areas. In terms of agricultural production the area has been largely used for cattle and sheep grazing during the summer months though there is also a record of managed goose grazing at least in the col at the head of Cwm Cadlan.

The boundaries of the characterised area largely follow those indicated in the historic landscapes register, though they have been drawn to match more explicitly the boundaries of the unenclosed and unforested moorland and also exclude the Penderyn quarry to the south-west. For convenience a fairly arbitrary boundary has been drawn to the north dividing the characterised area from the Mynydd y Garn character area, along the line of the A4059 trunk road and a footpath across the moorland.

Most of the area is registered Common Land, with the exception of parts of Mynydd-y-glog at the southern end of the area, part of Cefn Cadlan north of Nant-maden. Until local government reorganisation in 1974 the area fell within the Breconshire civil parishes of Cantref and Penderyn.

Key historic landscape characteristics

Extensive area of largely unimproved moorland though some areas of rough grazing at the southern end of the area, on the southern and western flanks of Mynydd-y-glog, are subdivided into generally large irregularly-shaped enclosures defined by drystone walls, mostly over about 8 hectares in extent, which appears to have been the subject of legal disputes about the right of Common of part of Mynydd-y-glog in the first half of the 19th century. Some of these have been further subdivided by straighter stone walls and by post-and-wire fences which appear to be of 19th- and 20th-century date. Some relict boundaries are also evident in this area, including an un-named encroachment with associated ruined buildings, perhaps of post-medieval origin, at a height of about 320 on a tributary of the Nant Melyn stream, whose fields extend to an area of about 8 hectares.

The place-name element carn (plural carnau, ‘cairn, mound, rock, heap’) occurs in the name Garn Ddu and Carn Pwll Mawr, but often appears to denote natural rock outcrops, particularly in limestone areas.

The element sych (‘dry, dried up’), which occurs in the stream name Nant Sychbant may indicate the periodic drying up of this stream where it runs along the porous Carboniferous limestone past various swallow holes to join the Afon Taf Fawr towards the south-eastern side of the character area.

The character area includes a number of important areas of ancient settlement and land use dating from the prehistoric period up to medieval times and beyond.

On the sheltered, east-facing slopes of Cadair Fawr, at the head of the Garwnant and Nant Ffynnonelin streams, overlooking Pant y Gadair and the Taf Fawr valley is a significant cluster of prehistoric hut circles and later house platforms and relict rectangular stone-built buildings. The settlement evidence here is associated with few traces of agricultural activity and may therefore represent temporary upland habitations between about 380-420 metres above sea level relating to the exploitation of upland pastures during the summer months between the earlier prehistoric period and the Middle Ages and possibly relating to more permanent settlements in the Taf Fawr valley.

A second important area of ancient settlement and land use, lying between a height of 350-450 metres, is to be found occupying the more sheltered southern slopes of Cefn Cadlan and the northern slopes of the col extending beyond the limits of the enclosed farmland at the head of Cwm Cadlan to the west and the now afforested but formerly enclosed farmland at the head of the Nant Aber-nant stream and its tributaries to the east. Here, there is evidence of land use represented by cairnfields (clusters of field clearance cairns) and by relict drystone boundaries, often concentrated in areas of between about a half and two hectares which appear to represent upland cultivation or pasture improvement. This activity is largely undated, but is most probably associated with settlement evidence, perhaps of an all-year-round nature, represented by hut circles and by rectangular building forms which again seem likely to mostly date to the period between the earlier prehistoric period and the Middle Ages.

A third significant area of ancient settlement and land use hugs the southern boundary of the enclosed land in Cwm Cadlan, to the east of the Cae’r Aglwydd, Wern-las and Beili-helyg farms and extending onto the more exposed northern slopes of Mynydd-y-glog, between a height of about 300-380 metres above sea level. Sites to be found here again include clearance cairns, occasional relict drystone boundaries, and dispersed hut circles and rectangular buildings.

Other small clusters of clearance cairns have been identified in the moorland on the southern and westerns sides of Mynydd-y-glog, at heights of up to about 320 metres above sea level.

A single burnt mound is recorded on the southern flanks of Cefn Sychbant comprising a characteristic horseshoe-shaped mound of burnt stones, adjacent to a marshy area. Mounds of this kind are best interpreted as middle to later Bronze Age sauna baths of some kind, though some may have been used as cooking sites.

The area also includes a number of important clusters of earlier prehistoric burial and ritual monuments, notably including burial cairns which can be distinguished from the clearance cairns by virtue of their larger size and also including a number of ring cairns of a kind which appear to have had both funerary and ritual functions during the early Bronze Age date, though none have been excavated in modern times. The association of some of these monuments with a medieval battle, suggested by the Breconshire historian Theophilus Jones on the basis of the placename Cadlan (‘battlefield, battle’), is now considered improbable. The monuments are generally between 6-20 metres across, and mostly lack distinctive features though one round cairn in the col above Cwm Cadlan shows possible traces of an inner kerb of stones and a central burial cist. The only find associated with the monuments is a sandstone disk found at this site. Some sites have been disturbed or damaged in recent centuries, sometimes for the construction of sheep shelters, but generally the sites are reasonably well preserved.

The monuments lie mostly above about 400 metres and appear in most cases to be prominently sited on either hill-crests or summits where they could be seen from a distance from a particular direction. Though no doubt further sites await discovery by more intensive field survey the known distribution suggests a number of meaningful clusters which appear to have significance in terms of early settlement and land use. The monuments in individual clusters sometimes appear to occur in pairs, spaced up to 40-50 metres apart, but are generally more widely spaced, at distances of 100-200 metres or more. Clusters can be identified on the west-facing slopes of Cadair Fawr overlooking the upper Hepste valley, on the west-facing slopes of the col at the head of Cwm Cadlan, on the south and south-east facing slopes of Cefn Sychbant and north-facing slopes of Mynydd-y-glog overlooking Pant Sychbant and the Taf Fawr valley, and on the south and west-facing slopes of Mynydd-y-glog overlooking the Cynon valley. Their general distribution complements rather than overlaps that of the traces of early agriculture and settlement noted above with which they are likely to be at least in part contemporary. None of the monuments appear to have recorded names of any antiquity.

Isolated, curvilinear or rectangular drystone sheepfolds, as for example on the eastern side of Mynydd-y-glog and on Cefn Cadlan, are probably of post-medieval date. Many of them are first depicted on Ordnance Survey maps of the 1880s.

Numerous disused limekilns and small quarries for extracting limestone are found on several of the limestone outcrops in the character area, notably on Cadair Fawr, the north side of Cefn Cadlan and the north side of Mynydd-y-glog. The kilns sometimes occur singly though are more often in pairs or clusters up to ten or more in number. Many of the kilns are visible only as grassed-over mounds, 1-3 metres high and 3-4 metres across, with a hollow at the centre, though in some cases structural details of drystone walling and the presence of one or more flues can be determined. Some kilns are associated with platforms or ramps by which they were loaded with limestone and with waste heaps. In most cases it is likely that the kilns produced lime for agricultural and building purposes. They are mostly undated but many are represented being out of use on Ordnance Survey maps of the 1880s and are likely to mostly date to the second half of the 18th century and the first half of the 19th century and to be associated with the other evidence for agricultural improvements that were carried out on farm on the adjacent lower ground during this period.

The area also includes a number of disused sandstone quarries on Garn Ddu and the western side of Cefn Cadlan which from cartographic evidence appears to have originated during the first half of the 20th century. Deposits of silica sand were also once worked at the Cefn Cadlan quarry.

The area is crossed by the line of the earlier 19th-century Hirwaun-Brecon turnpike road (the modern A4059), the surviving remains of which include several small roadside quarries and milestones. The western end of the area is clipped by the course of the former railway used in the construction of the Ystradfellte Reservoir in the early 20th century. The southern part of the area is crossed for a distance of about 2 kilometres by the route of a modern gas pipeline whose 20m-wide wayleave can still be traced to the point it joins the Bryn Du gas works just to the south-east of the character area.

Peaty areas, buried soils and other sediments in the area have a considerable potential for reconstructing past land use and environmental change.


Historic Environment Record; Ordnance Survey 1st edn 1:2,500; Jones 1930; Leighton 1997; Morgan and Powell 1999; Selwood 2000; Soil Survey of England and Wales 1983; RCAHMW 1997; Webley 1954.

For further information please contact the Clwyd-Powys Archaeological Trust at this address, or link to the Countryside Council for Wales' web site at

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