Monument Type(s):

• BOUNDARY BANK (Early Saxon to Mid Saxon - 410 AD to 800 AD)
• DYKE (DEFENCE) (Early Saxon to Mid Saxon - 410 AD to 800 AD)
• FRONTIER DEFENCE (Early Saxon to Mid Saxon - 410 AD to 800 AD)
• LYNCHET? (Medieval to Post Medieval - 1066 AD? to 1901 AD?)

Summary

The earthwork remains of a section of Offa's Dyke, to the W of Chapel Lane, Trefonen.

Related records

Associated Finds: None recorded

Associated Events

• ESA7629 - 2008 WB on pits dug for water pipeline works, adjacent to Chapel Lane, Trefonen by Andy Wigley
• ESA9793 - 2022 Trial trenching on W side of Trenant Chapel, Trefonen by CPAT (Ref: 21/05983/FUL)

Description

The earthwork remains of a section of Offa's Dyke, were noted in the garden to the east of 'Harcombe', Trefonen during a site visit in October 2015. No access was possible to the garden itself, but the site was photographed from the public domain. A mature orchard exists on the west flank of the earthwork, and mature trees are growing on the southern terminal. The sub-rounded 'terminal' of the earthwork was clearly visible, with the earthwork standing to an approx. maximum height of 1.2m. <1>

This feature is marked as an earthwork on modern Ordnance Survey Master Map; the top of slope and base of slope is marked and the sub-rounded form of the terminal is clear. <2>

In addition, the shape of the burial ground associated with Carneddau Chapel (PRN 14320) appears to preserve the line of the dyke. This is noticeable as a linear 'strip' with a slightly convex alignment on the east side. This churchyard appears to preserve a 'domed' profile in Google Earth Street View imagery, which was noted slightly during the site visit. A collection of linear boundaries are shown on 1st edition Ordnance Survey mapping along Chapel Lane, running S of the scheduled section of the dyke (PRN 30729). <3><4><5>

A site visit/watching brief was conducted at Chapel Lane, Trefonen in 2008 to inspect pits dug within the carriage way of road for the pruposes of renewing an existing water main and connecting domestic water supplies. The site lay partially adjacent to a scheduled section of Offa's Dyke and was undertaken in relation to terms of Scheduled Monument Consent. No remains associated with the dyke were observed to have been directly impacted by the work, with the renewal of the remain occurring outside the eastern extent of the dyke. However, it was observed that the properties at the southern end of Chapel Lane appear to overlie the line of the Dyke. Observations during the site vsit suggest that groundworks associated with ongoing renovations at Offa's Cottage have further removed part of the dyke without archaeological record. <6>

Manual excavation of a 4 x 1m trench in the back garden of Trenant Chapel (centred on SJ 2596 2691) was excavated in March 2022 to ascertain whether a proposed extension on the west side of the chapel would harm the buried remains of Offa’s Dyke. The trial trench revealed natural geology as comprising a sandy silt with occasional sandstone at a depth of c.0.4 -0.5m below current ground surface. Most of the trench contained a horticultural deposit above the natural with 19th – 20th century artefactual evidence within in, and a series of possible cultivation slots into the underlying natural. At the western end of the trench, however, a more compact deposit of sandy silt overlying a gravelly layer was found at 0.3m below the ground surface, and this deposit terminated abruptly c.1m from the western end of the trench. It is interpreted as a lynchet, or terrace edge, and historic mapping shows a property boundary in the approximate location of this feature. Historic mapping and field survey also confirmed the line of Offa’s Dyke as extending beneath the houses, chapel and burial ground that form the western side to Chapel Lane. It was concluded that there would be no harm to Offa’s Dyke from the proposed extension. <7>

Sources

Search results generated by the HBSMR Gateway from exeGesIS SDM Ltd.