Archaeological

Introduction

While only two recorded archaeological sites were known to exist within the proposed development footprint of the M28 Cork to Ringaskiddy Project prior to development, the Environmental Impact Statement (EIS) acknowledged the potential for the project to impact on buried, unknown archaeological remains. To this end, the EIS proposed a managed programme of archaeological mitigation measures to first identify and then preserve by record any such remains as may be found to exist. These mitigation measures were approved by An Bórd Pleanála when granting approval for the scheme and are in line with the 2017 Code of Practice for Archaeology agreed between the Minister for Arts, Heritage, Regional, Rural and Gaeltacht Affairs and Transport Infrastructure Ireland. To oversee all archaeological investigations, Transport Infrastructure Ireland assigned a Project Archaeologist to the scheme and Cork County Council appointed a Resident Archaeologist. In line with the National Monuments (Amendments) Act 1930-2014, all archaeological investigations were undertaken under the terms of directions issued by the Minister of Housing, Local Government and Heritage, in consultation with the National Museum of Ireland, and as per methodologies agreed with the National Monuments Service.

Archaeo-geophysical surveys

Cork County Council commissioned a series of archaeo-geophysical surveys to remotely record specific properties (mostly magnetic and electrical resistance) of the underlying soils, to help identify features of archaeological potential. Between October 2020 and April 2021 Earthsound Geophysics Ltd surveyed approximately 76 hectares of the M28 route. Some smaller supplementary surveys were also carried out by ArchaeoPhysica Ltd, J.M. Leigh Surveys Ltd and Dr. Ger Dowling, some prior to and others after the project commencement.

Archaeo-geophysical surveying: a quad bike tows the sensitive survey instrumentation at Barnahely (top) and an example of the map-plot output from another location (bottom) (Image: Cork County Council. Drawing: Earthsound Geophysics)

Appointment of Consultant Archaeologists

Following a competitive tender process, Cork County Council awarded the M28 Archaeological Consultancy Services (Stage [i]-[iv]) Contract to Rubicon Heritage Services Ltd. The archaeological services involved surveys, testing, excavations and post-excavation analysis, reporting and dissemination. Rubicon have sub-contracted TVAS (Ireland) Ltd to assist with elements of the archaeological investigations. Separately, Archaeological Management Solutions Ltd were appointed by Cork County Council to undertaken wade surveys

Surveys and Testing

This stage involved archaeological surveys (built heritage surveys, townland boundary surveys and in-water wade surveys) and archaeological test trenching.

Built Heritage Surveys

Various upstanding remains of cultural heritage significance along and immediately adjacent the M28 route were the subject of built heritage surveys. These included demesne grounds and boundaries, dry-stone walling, some vernacular structures, part of an old railway line and bridge, a gate lodge and Radaville House.

Wade Surveys

Wade surveys (including in-water metal detection) were undertaken by Archaeological Management Solutions Ltd, between late 2021, and during April 2022, at eight locations across the scheme, mostly along streams but some estuarine areas.

Built heritage 3D survey of Porspect Villa gate lodge located immediately adjacent the scheme (Rubicon Heritage)

Archaeological wade survey of a stream course (AMS Ltd)

Townland boundary surveys

Townland boundaries intersected by M28 alignment were surveyed to serve as a record.

Archaeological Testing

To help further identify buried remains, an extensive programme of archaeological testing was undertaken, in phases: an initial phase, where the bulk of testing was undertaken, during 2022, with a second phase in March 2023. Some further testing was carried out in late 2023 and in 2024. Combined, a total of c. 55,500 linear metres of test trenches were investigated across the scheme. Testing typically involved the mechanical opening of a centreline test trench with regular off-shoot trenches to the scheme boundary, all under strict archaeological supervision. The area exposed by testing typically equated to a minimum 12% test sample of the land traversed. Any significant features or finds of archaeological potential were recorded and mapped for further investigation. In all, testing revealed 127 areas with features of archaeological potential. For management purposes, these were collated into 38 sites of archaeological potential. The ancillary testing identified 10 further areas of archaeological potential, but in areas where they could be protected from construction works.

Townland boundary recording (Rubicon Heritage)

Extensive archaeological test trenching at Ballinrea (Rubicon/TVAS)

Preparing sites for excavation

Where test trenches identified features of archaeological potential, these locations were further exposed by removing topsoil around them to identify the full extent of the archaeological remains and to prepare the sites for archaeological excavation.

Archaeological excavations

Archaeological excavation of the 38 sites commenced in early 2022 and ended in late 2024. Sites ranged in date from the early prehistoric to the early modern times. Based on the preliminary findings, some key sites include the following:

Ballyhemiken 3 – house(s) of some of the earliest farmers in the region (c. 3700 BC)

Situated on a plateau that overlooks the surrounding countryside, the site contained the foundation remains of at least one Early Neolithic house (possibly two) and a potential ancillary building. Stone tools, cereal grains and Early Neolithic pottery were identified in the foundation of the house indicating that the site was likely the farmstead of an early prehistoric family, and likely one of the earliest farming families to have settled the area.

Prehistoric houses (Bronze Age?) at Barnahely 2 and Raffeen 2

Two sites, at Barnahely 2 and Raffeen 2, contained what may prove to be Bronze Age roundhouses. Each was likely the home of a single-family unit who lived on the Ringaskiddy peninsula in prehistoric times. Only the post-holes remain to indicate the outline of the possible houses.

Barnahely 2 –Bronze Age grain storage pits

A concentration of suspected Bronze Age grain storage pits was discovered at Barnahely. These pits contained significant quantities of charred grain and several quern stones, which would have been used to grind the grain to make flour.

Examples of fulachtaí fia/burnt mounds from

Several fulachtaí fia/burnt mounds were excavated across the scheme. A large example, a previously known site, was unearthed at Shannonpark. This site type typically dates to the Bronze Age.

Remnants of Early Neolithic house at Ballyhemiken 3 (Cork County Council)

Bronze Age grain storage pit at Barnahely, with quern stone visible in base of bit (Cork County Council)

Burnt mound of heat-shattered stone exposed at Shannonpark (Cork County Council)

Carrigaline Middle 1 – Suspected Bronze Age cemetery and early medieval enclosure

This was a multi-period site containing a Bronze Age flat cemetery with 13 cremations (including one urn cremation and two stone cists) and a suspected early medieval double-ditched (bi-vallate) enclosure.

Shanbally 6 – Ring-ditch with cremated bone

At this site archaeologists found the remains of a prehistoric ring-ditch, the contents of which included cremated remains, charred seeds and iron slag. Though not yet scientifically dated, suspected burial monument is likely to be of Iron Age in date.

Cereal-drying kilns at Ballinimlagh 2, Ballinrea 6, Ballinrea 5, Shannonpark 3 and Shanbally 4.

Cereal-drying kilns were discovered at various sites. None of the examples have been dated, as yet, but such sites typically date to sometime from the Iron Age to the late medieval periods.

Barnahely 2 – Early medieval enclosure complex

By far, the stand-out site from the M28 project is the multi-enclosure complex at Barnahely 2. Three ringforts, two containing souterrains, and a later enclosure and associated cereal-drying kiln were found. Ringforts are defended farmsteads of early medieval date. The souterrain within one of the ringforts appears to have utilized an underlying cave system. A large quantity of artefacts was uncovered from the excavation, as well as charred plant remains, animal bone, marine shell, whale bone, and metal working debris, which, collectively, provide evidence for several crafts, including metal working, glass working, leather working, comb making, lignite working, woodland harvesting, textile production and more. This suggests that at least one of the ringforts was high status.

Bronze Age cist cremation burial at Carrigaline Middle (Rubicon Heritage)

Prehistoric ring-ditch under excavation at Shanbally (Cork County Council)

Examples of cereal-drying kilns from Ballinrea (left) and Shannonpark (right) (Rubicon Heritage)

Aerial view of early medieval enclosure complex at Barnahely 2 (Rubicon Heritage)

Dawn view of souterrain at Barnahely 2 (Rubicon Heritage)

Decorated bone spindle whorl (left) and bone comb fragment (right) from Barnahely 2 (Rubicon Heritage)

Ballinrea 5 – Multi-phased, early medieval enclosure with multiple souterrains

At Ballinrea, on elevated ground with expansive views to the north and east, excavations revealed a substantial enclosure of likely early medieval date. The enclosing ditch appears to have been constructed in phases, culminating in a large, ‘plectrum-shaped’ enclosure. Entered via the east, the enclosure contained up to 12 suspected souterrains (underground, post-supported storage areas) flanking the enclosing bank (very little of which survived) and ditch. The high number of souterrains suggests the enclosure served a specialized function in the early medieval period.

Barnahely 3 – early medieval house and souterrain

The principal features at the site comprised two sub-terranean chambers (probable souterrain) and the foundation remains of c. 6 m-diameter circular building (house?), all likely dating to early medieval period. An unusual rectilinear slot foundation was found to the south of the building, its function remains uncertain.

Ballinimlagh 3 – multi-period enclosure (late medieval to post-medieval)

A substantial, sub-rectangular, ditched enclosure was identified at Ballinimlagh. The evidence suggests the site originated as a late medieval moated enclosure, likely constructed by colonists arriving as part of the Anglo-Norman conquest of Ireland. The evidence further suggests that the enclosure and associated paddocks remained in use as a farmstead into the 17th century. Documentary evidence records that the farmstead, in 1642, was owned by a William Greene who had his farmstead plundered. A written deposition recorded on his behalf states that the following were forcibly stollen from him: his cattle, horses, the corn ‘in the house’, his linen, his woolen, clothes and household goods, and his garden fruits; a total loss of 28 pounds and 18 shillings. Contemporary documentary account suggests this same William Greene had debts to others he was unable to pay. Though unstated, it is plausible that he was unable to maintain his Ballinimlagh farmstead as a result and that the site was abandoned shortly after.

Aerial view of large early medieval enclosure from Ballinrea (Rubicon/TVAS)

Aerial view of suspected early medieval house and associated souterrain at Shanbally (Rubicon Heritage)

Aerial view of moated enclosure at Ballinimlagh during excavation with inset showing two sides of a medieval coin from the site (Rubicon/TVAS)

Ballyhemiken 2 – Large charcoal production kiln

The most striking feature from the site was a large, elongated charcoal production pit. Measuring c. 15 m long, 2.5 m wide and 0.7 m deep, this example far exceeds the more typical size range for excavated examples of such features in Ireland. The base of the pit was highly scorched. These sites were used to slowly burn wood (typically oak) to produce charcoal for use in metal-working. The charcoal-production pit is likely medieval or post medieval in date and must have produced large volumes of charcoal.

Shannonpark 1 – 17th-century forge building, with associated cobbled yard and old road

Remains of a stone-built forge building, with brick and stoen floor and cobbled yard were found at low-lying ground at Shannonpark. Finds includes 17th century pottery, glass, metal-working debris and metal, as well as clay pipe fragments and flint objects. Uncovered immediately adjacent was an old road, likely contemporary with the forge. Both the road and forge are believed to be contemporary with a 16th/17th century house (CO086‐062) located to the west, denoted as ‘site of Old Court’ on the 1842 6‐inch OS mapping.

Barnahely 1 – ‘Ha-ha’ ditch (part of Castle Warren demesne)

The tower house at Barnahely was occupied by the deCogan family until 1642, when the castle garrison surrendered to Lord Inchiquin. Ownership changed hands several times during the turbulent years of the mid-17th century. Barnahely Castle and its estate came into the hands of the Warren family in 1796, who construction a late 18th century house (‘Castle Warren’) directly onto the foundations of the earlier Barnahely castle, using stone from the castle’s bawn wall. This was the period of the ‘Protestant ascendancy’, where there was a boom in the construction of classical houses with demesne landscapes and associated large farms, the design of which was strongly influenced by social and architectural ideas from Britain and mainland Europe. Excavations at Barnahely 1 revealed an example of one such landscape design element known from France and England and spreading in popularity at that time—the ‘ha-ha’ ditch. These were boundaries (typically a ditch and retaining wall) cut into the ground to prevent unwanted animals entering the demesne lands, while maintaining uninterrupted views from the big house. The term ‘ha-ha’ supposedly derived from the sentiment of humorous surprise visitors expressed when seeing the hidden boundary on closer inspection.

Very large charcoal production kiln from Ballyhemiken (Cork County Council)

Remnants of cobbled yard associated with a 17th century forge discovered at Shannonpark (Cork County Council)

Aerial view of 'ha-ha' ditch at Barnahely, with associated sunken stone wall designed to ensure an unhindered view from Castle Warren in the background (Rubicon Heritage)

Post-excavation analysis, reporting and dissemination

With all the on-site archaeological excavations now concluded, the process of off-site post-excavation analysis and reporting has been underway since November 2024. This will involve specialist analysis of the artefacts and environmental samples recovered (e.g. grain and charcoal), as well as obtaining radiocarbon dates and undertaking further detailed research. This work will culminate in the production of excavation reports and the publication of a book on the results. In time, the site archive (artefacts and documentation) will be stored with the relevant statutory authorities, thereby ensuring that all the findings are preserved by record.