CPAT Regional Historic Environment Record
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Pigwn prehistoric monument complex

Primary Reference Number (PRN) : 12386
Trust : Clwyd Powys
Community : Llywel
Unitary authority : Powys
NGR : SN83193118
Site Type (preferred type first) : BRONZE AGE PREHISTORIC MONUMENT COMPLEX
Status : scheduled monument

Summary :
An important group of prehistoric funerary and ritual monuments is sited on a broad ridge to the east of Pigwn Roman marching camps.

Description :
(SC 4;Figs 55-6) On TRECASTLE MOUNTAIN, on an undulating plateau sloping gently towards the N. at 370 m above O.D. are the remains of two circles (SC 4 i and ii), a cairn (SC 4 iii), three scattered groups of stone (SC 4 iv) and a recumbent standing stone (SC 4 v). The stone alignments and monolith are not certainly anthropogenic in origin. Lying about 400 m E. of Y PIGWN Roman practice camps, the circles may at one time have acted as waymarkers on the open moorland beside the course of the former coach road (based upon the Roman route) from Brecon to Llandovery. Curiously they are not depicted upon the earliest editions of the Ordnance Maps1 and William Rees, the celebrated Swansea scholar-printer, said the group had been found in 1849 by John Rhys Jones.2 Circles (SC 4 ii-iii) and (SC 4 ii) were not planned until the turn of the century.3 Several later fieldworkers also surveyed the sites,4 variously ascribing their functions to ritual,5 and more commonly in recent years, to astronomical uses.6 It is still possible to detect an E.-W. track actually passing through the site, immediately N. of, and slightly truncating the more S. circle.
The whole complex lies within a curvilinear enclosure comprising a substantial bank and ditch, the southern length of which runs roughly E.-W., and its E. boundary runs N.-S., about 50 m E. of the recumbent stone. This E.-W. bank continues in a westerly direction to the Roman Fort, where its overall alignment coincides almost precisely with that of the N. bank of the interior fort, although the two do not appear to join. The bank's dating is unclear, but it seems unlikely to have been Roman and presumably marks the boundaries of a medieval agricultural or pastoral enclosure.
Not only is the area around the Roman Fort heavily mined by quarrying, but minor quarries pock-mark this entire area. The activity of stone-drawing from the common was probably responsible for helping denude all upstanding stone-filled monuments of such cairn material as might have been notionally reveted by the surviving orthostats which make up the circles. As the area was also in military use for some time after the Second World War, it is possible that some of these pockmarks and tracks may derive from that activity.
(SC 4 i) About midway between the two upstanding circles, are three stones, which if plotted out would lie upon the circumference of a about 10.6 m in diameter. They comprise a block 0.64 m by 0.58 m by 0.4 m high a fallen pillar 0.5 m by 0.23 m by 0.91 m high (when upright) and a block 0.86 m by 0.55 m by 0.48 m high. Its location suggests that this could be the fugitive remnant of a feature seen more complete during the 1930s by Grimes.7
(SC 4 ii) Of the surviving circles, the smaller, more westerly is 7.9 m in diameter and consists of four irregularly spaced massive slabs now leaning outwards. Each is about 0.6 m wide and stands 0.9 m high. The ground around the orthostats is very badly eroded by sheep, to form deep hollows which have collected water.
(SC 4 iii) The second and larger, northeastern circle, is 23.1 m in diameter N.E.-S.W. by 22 m and consists of twenty-one uprights form 0.1 to 0.5 m high, with at least five stone holes, give a regular spacing at intervals of about 2.6 m. Some stones are well weathered, or even frost-shattered into angular stumps, whereas others are more boulder-like in form. Between two orthostats rather larger than the rest on the S.E., the Old Red Sandstone is exposed over an area about 3 m long and 1 m wide (along the cairn perimeter). On the S.W. is a gap of 5.5 m between stones which it has been suggested8 may have been an entrance. There is a slight irregular mound about 6-7 m in diameter lying towards the northern part of the site, which may be all that remains of a former cairn infill, or alternatively may represent the capping of a near-central burial.
(SC 4 iv) A stone-built cairn, see (RC 35).
(SC 4 v) Depending upon the number included in the grouping, there are four or five groups of outlying uprights, none of which are certainly associated with the circles, and indeed, some or all may even be natural. Running between the two circles and aligned N.-S. along their E. perimeters are three stones. To the immediate W. of the S.W. circle are two more, and beyond, to the S. of it, two further pairs of apparently unrelated stones. Roughly at right angles to this grouping, and about 40 m from it, is a further alignment of four stones. It has been suggested9 that at one time, at least some of these stones may have formed part of a field boundary.
(SC 4 vi) At 385 m above O.D. is a recumbent standing stone with a pointed end, lying to the E., some 125 m from the northeastern circle and 143 m from the southwestern. If the stone ever had any significance within this monument group, it would probably have projected above ground about 1.5 m high, at an oblique angle. However, the stone appears to have formed part of an outcropping band of sandstone, and its presence here may be adventitious. It measures 1.16 m wide by 0.74 m thick and the original stump, now much weathered and rounded, is at least 1 m thick. About 10 m due S. of this there is another stone (not marked upon the plan), also with an almost vertical bedding plane, and about 1 m in length. It appears to form part of the same rock exposure.
1. MS O.S.Maps, Brit. Lib. (1818);A.P.s, C.U.A.P. QJ 15,17;A.P., R.C.A.M., 88 MB 69-72.
2. The site is first noted by W. Rees, Arch. Camb. 8 (1854), pp.125-134.
3. W. Ll.Morgan, Proc.Swansea Sci.Soc. (1907-8), pp.146-9 (plan)
4. Grimes, Map L.B.M.;Stone Circles, pp.135-6;Barnatt, Stone Circles, p.391,nos 13:45-6.
5. Burl, Stone Circles, pp. 260-2, 369 (plan).
6. Thom, Megalithic Sites, table.
7. An unsigned MS of 30th July 1933, which includes sketch plans of two circles and notes about them written upon Castle of Brecon Hotel notepaper, probably in the hand of W.F.Grimes, suggests there were at that time many more outlying stones than later survived. The writer felt that a handful of stones may have at one time have belonged to an outer circle. It is difficult to correlate the second circle described in this MS with the known sitings. It had 8 peristaliths, was some 95 feet [about 29 m] in diameter, also had a slightly raised centre, and apparently lay roughly equidistant between the known, larger, N.E. circle, and the N.W. corner of Y PIGWN Roman Camp (Lloyd MSS).
9. See O.S. card SN 83 SW 6 and Grimes loc.cit. n. 4 above.
8. W.E.Griffiths in R.C.A.M. files.
9. By the O.S.;See O.S. Card SN 83 SW 6.
RCAHMW, 1995 - Draft Inventory description

An important group of prehistoric funerary and ritual monuments is sited on a broad ridge to the east of Pigwn Roman marching camps. The most significant and impressive sites are two adjacent stone circles (PRNs 50467 and 50275) 40m apart, with a possible small stone alignment nearby (PRN 50276), together with a large recumbent stone (PRN 12388) 80m to the east, although this may be natural. The remains of a possible third circle (PRN 12387) lie 180m to the northwest. There are also two burial cairns (PRNs 742 and 743) in the same area, both of which have been excavated, probably by John Holford in 1824, who found two cinerary urns in the larger cairn and an undecorated biconical pygmy cup in the other. (CPAT 2005)

Sources :
Jones, N W , 2005 , Prehistoric Funerary & Ritual Sites; Central Brecknock, Project Report ( © Clwyd Powys Archaeological Trust)
Royal Commission on the Ancient and Historical Monuments of Wales , 1995 , An Inventory of the Ancient Monuments in Brecknock (Brycheiniog); The Prehistoric and Roman Monuments, Part i - draft text
Royal Commission on the Ancient and Historical Monuments of Wales , 1997 , An Inventory of the Ancient Monuments in Brecknock (Brycheiniog); The Prehistoric and Roman Monuments, Part i
1. MS O.S.Maps, Brit. Lib. (1818);A.P.s, C.U.A.P. QJ 15,17;A.P., R.C.A.M., 88 MB 69-72.
2. The site is first noted by W. Rees, Arch. Camb. 8 (1854), pp.125-134.
3. W. Ll.Morgan, Proc.Swansea Sci.Soc. (1907-8), pp.146-9 (plan)
4. Grimes, Map L.B.M.;Stone Circles, pp.135-6;Barnatt, Stone Circles, p.391,nos 13:45-6.
5. Burl, Stone Circles, pp. 260-2, 369 (plan).
6. Thom, Megalithic Sites, table.
7. An unsigned MS of 30th July 1933, which includes sketch plans of two circles and notes about them written upon Castle of Brecon Hotel notepaper, probably in the hand of W.F.Grimes, suggests there were at that time many more outlying stones than later
survived. The writer felt that a handful of stones may have at one time have belonged to an outer circle. It is difficult to correlate the second circle described in this MS with the known sitings. It had 8 peristaliths, was some 95 feet [about 29 m] in
diameter, also had a slightly raised centre, and apparently lay roughly equidistant between the known, larger, N.E. circle, and the N.W. corner of Y PIGWN Roman Camp (Lloyd MSS).
9. See O.S. card SN 83 SW 6 and Grimes loc.cit. n. 4 above.
8. W.E.Griffiths in R.C.A.M. files.
9. By the O.S.;See O.S. Card SN 83 SW 6.
Llywel (E), Traean-glas (C)

Events :

Related records
CPAT Historic Environment Record (HER) 12386

Compiled date : 15-11-1999


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Archaeological data, from the Historic Environment Record, supplied by The Clwyd-Powys Archaeological Trust in partnership with Local Authorities, Cadw and the partners of ENDEX © CPAT, 2025 (and in part © Crown, 2025). It is intended to be used for private research only and is not for use as part of commercial projects. If you wish to use this information for publication in printed or multimedia form or to compile resources for commercial use, prior permission must be obtained in writing. Use of this information is subject to the terms and conditions of access to HER data published on CPAT's website. Please contact the HER if you have any further questions regarding this information. Please quote the Primary Reference Numbers (PRNs) in any correspondence.

May 13, 2025, 4:58 pm - File produced for Archwilio from CPAT's Regional HER.
Clwyd-Powys Archaeological Trust, The Offices, Coed y Dinas, Welshpool, Powys, SY21 8RP
tel (01938) 553670, email her@cpat.org.uk, website www.cpat.org.uk

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