New discoveries at Trefael Stone in Wales

Trefael Stone and illuminating the cupmarks. Image: © Adam Stanford and WRAO

Trefael Stone and illuminating the cupmarks. Image: © Adam Stanford and WRAO

Dr George Nash
Involved in academic and commercial archaeology, employed as an Associate Archaeologist with SLR Consulting. Works on the final two years of the part-time degree in archaeology at the University of Bristol.

By the Welsh Rock-art Organisation (WRAO)

The Trefael Stone, standing in a large rectangular field north of the village of Nevern in west Pembrokeshire, until 2010, was considered to be a standing stone, one of a number that occupy this ancient landscape. Used as a cattle rubbing stone, it measures around 1.2 m in height and over 2 m in length and has on its southern face up to 75 cupmarks.

The cupmarked Trefael Stone. Image: Adam Stanford

The cupmarked Trefael Stone. Image: © Dr George Nash & WRAO

It was believed as far back as 1972 that this stone belonged to a destroyed burial monument; however, only excavation would confirm this. The current team initially applied for Scheduled Monument Consent (SMC) to excavate a small slot that would run parallel to the cupmarked surface. The rationale for this was to merely record the rock art. Fortunately CADW, the national heritage organisation for Wales, responsible for this monument had a slightly different idea that would involve the excavation of a large trench immediately south of the stone.

Planning the tightly compacted cairn located east of the Trefael Stone. Image: Adam Stanford

Planning the tightly compacted cairn to east of the Trefael Stone. Image: © Adam Stanford & WRAO


It is from this initial enquiry that a long-term project started to take shape. In November 2010 the first investigations in and around Trefael commenced and the initial ideas as to what the monument was, started to materialise. Based on the results from that first encounter we realised that Trefael was rather special.

2010 season

Mag survey around the Trefael Stone: Credit: Dodds, Dell and Moore

Magnetometry survey around the Trefael Stone: Credit: Dodds, Dell and Moore

Last year and in extremely inclement weather the Trefael team, led by Dr George Nash, Adam Stanford and Tom Wellicome uncovered the probable remains of a Portal Dolmen, one of Western Britain’s oldest monument types. This rather damp excavation season, comprising a 4 m square excavation trench revealed a significant cairn deposit on the SE side of the stone.

Mudstone bead from cairn deposit east of Trafael. Image: Adam Stanford

Mudstone bead from cairn deposit. Image: © Dr George Nash & WRAO

This feature was first identified through geophysical survey. In addition to this tightly-compacted cairn material, a probable Neolithic surface was exposed, but no diagnostic material was found. However, the cairn material did sit directly over this surface.

Artefacts were limited to a few sherds of historical pottery including a nice green glazed flagon neck and two perforated shale beads, probably Mesolithic in date.  The presence of such artefacts reflects the importance of this site several thousand years before the Portal Dolmen was constructed!  What is more, the Trefael Stone itself appears to have formed the capstone for the Portal Dolmen and this was probably reused as a standing stone (or menhir) during the Early/Middle Bronze Age.

A spectacular 2011 season

The second season at Trefael in South West Wales has just finished and the results are spectacular.

Clear geophysical survey results allowed the team to specifically target areas where significant archaeology might occur. A geophysics team led by Les Dodd, Phil Dell and Bryan Moore geoprospected 26 x 20 metre sectors in which a number of clear anomalies were detected. Two such areas were located to the north and west of the monument and were subsequently excavated by the WRAO team.

Elsewhere a large number anomalies were recorded in the field to the south of the monument as well as potential archaeology within the SW corner of field in which the Trefael Stone stands. It is hoped that when the results of the geophysical survey are refined, a clear picture of the prehistoric ritual landscape will emerge.

A ritual landscape

Probable Neolithic pottery from Trench 1. Image: Adam Stanford

Probable Neolithic pottery from Trench 1.  Image: © Adam Stanford & WRAO

Uncovered in a trench immediately north-west of the Trefael Stone were a number of indicators to suggest further that we were digging a Neolithic burial-ritual monument, probably the Portal Dolmen that was suggested during the first year of excavation.

Finds included several sherds of Neolithic pottery, probably Grooved Ware, along with possible fragments of human bone. The survival of both the pottery and bone is remarkable in that the local soils are extremely acidic and nothing should really survive. This material along with a few pieces of flint appears to have been dispersed amongst disturbed (ploughed-out) cairn material. It is probable that the area in which the pottery and bone were recovered represents part of the former chamber. Due to this unexpected discovery and legal and technical complexities that go with it the team decided to continue excavations next year.

Ongoing excavation within Trench 2 around a disticnt linear feature. Image: Adam Stanford

Ongoing excavation within Trench 2 around a disticnt linear feature. Image: © Adam Stanford & WRAO

Linear stone alignment

Discovered within the second trench (and based on the results of the geophysics survey) was a linear stone alignment, originally thought to be a prehistoric field boundary.

Further excavation, though supervised by archaeologist Catherine Rees revealed this curious feature to be part of a burial cist, probably Bronze Age in date. Thankfully, directly associated with this feature was a large quantity of charcoal and an array of small finds.

Due to the complexities of this trench plus the potential for the discovery of human remains it was decided that more careful work was required and may be an extension to the current trench dimensions. As a result a protective membrane was placed over this Trench and Trench 1 and work will resume next year.

Recording and understanding the cupmarks

Completed this year was the recording of all the cupmarks on the Trefael Stone – numbering over 75 individual gouges of varying size.  The work was halted last year due to adverse weather conditions.  Their meaning still remains a mystery but it is considered that based on the linearity of several groups, these enigmatic carvings were undertaken in a series of phases.

Recording the central section of the stone. Image: Adam Stanford

Recording the central section of the stone.  Image: © Dr George Nash & WRAO

In addition to the excavation programme, geophysical survey also revealed in a field to the south and east of the monument further anomalies suggesting that the Trefael monument is not alone and is in fact part of a much larger ritualised landscape.

Evidence for a wider ritualised landscape is further endorsed by the ‘excavation’ from a nearby hedge boundary of a missing standing stone which disappeared off the archaeological radar some 30 years ago. Up until then the stone was present on Ordnance Survey mapping, standing less than 35m from the Trefael Stone.

The missing standing stone. Image: Adam Stanford

The missing standing stone.  Image: © Dr George Nash & WRAO

This single monolith which once stood in the northern part of the field measured around 2m in length and is probably made from Preselite, the same stone used to construct one of the circles at Stonehenge.

Prior to uncovering pieces of this enigmatic jigsaw, it was considered that the 2011 excavation would be the final season’s work. However, the uncovering of such a wealth of late prehistoric archaeology has created a new set of research questions. Thankfully the landowner in giving her consent to allow the WRAO team back for another season and the hunt will continue!

In the 2012 season we will continue the investigations within the two trenches opened this year and also undertake further trenching in and around the immediate area.

George Nash explains the site

More information: