2024:556 - Derryarkin, Derryiron, Coolcor, Coolville, Ballyburly, Greenhills, Bunsallagh, Derrygreenagh, Knockdrin, Wood, Killowen, Corbetstown, Carrick, Garr and Dunville, Offaly

Archaeological monitoring and excavation at the Yellow River Wind Farm development, Rhode, Co. Offaly, has been completed. Work commenced in November 2022, and on-site archaeological work finished in August 2024. Post-excavation work is in progress at the time of writing.

During the course of monitoring the project, a number of archaeological sites were identified in the townlands of Greenhills (Site 1), Killowen Wood (Site 2), Carrick (Sites 4 and 5), and Killowen (Site 6). In January 2023, testing under Licence No. 22E0909 identified an extensive archaeological site in the townland of Wood (Site 3). During the construction phase at Yellow River part of this site was preserved by record and part preserved in situ under Licence 22E0822 following the submission and approval of a Conservation Management Plan to the National Monuments Service.

The identified archaeological sites comprised the poorly-preserved remains of fulachtaí fiadh (Sites 1 and 4), as well as evidence for iron production, furnaces and charcoal-production pits (Sites 2 and 5). Large quantities of slag were recovered from the iron production sites.

Although considerably impacted by post-medieval agricultural activity, Site 3 comprised a multi-period site with potential evidence for prehistoric, later medieval and post-medieval activity. The partial in situ remains of a single human adult inhumation were also uncovered. A bone sample submitted for advance radiocarbon dating and stable isotope analysis returned a date of between AD cal. 1030–1176, with a median date of AD 1102 (936±31BP; UBA-52636; Alter No. 7997). The human remains had been impacted by the construction of a large, trapezoidal enclosure defined by a relatively shallow fosse, with an entrance at the south-west (overall external dims: 46m long north-east/south-west and between 29m and 40m in width; the fosse was an average of 1.25m in depth and between 2m and 2.8m in width). Three large post-holes were located at the entrance. Additional post-holes, slot trenches, pits and hearths were identified from within the excavated area of this enclosure. A larger but morphologically similar monument is located c. 400m to the south-east and has been classified as a moated site (RMP OF004-009).

A substantial multi-phase linear feature, with an east-west orientation, was identified immediately to the south of the trapezoidal enclosure. It has been interpreted provisionally as a mill race, or water management feature, and may also be associated with the alteration in course of the Yellow River immediately to the west. The mill race comprised a large, flat-bottomed ditch, with a dry stone revetment in the south-faction section (approx. dims: min. 150m east-west; between 2.5–3.1m wide; av. 1m deep). This was recut by a later ditch feature, which appeared to be coeval with the large trapezoidal enclosure.

The north-eastern corner of the trapezoidal enclosure cut a smaller but still substantial circular enclosure, which was only partially excavated.  Elsewhere in Site 3, the remains of a wooden structure, possibly associated with eel fishing, was excavated at the edge of the old course of the Yellow River, on the western side of the site. Furthermore, two pits contained the partial remains of animal burials. A rectangular trough and stake-holes located on the western side of the site are likely to be associated with a fulacht fiadh. A large rabbit burrow was also noted at the north-western end of the site, which was partially excavated, as it may be associated with the later medieval phase of activity here.

The artefactual assemblage from Site 3 included a small amount of stone tools and debitage, the complete upper stone of a rotary quern, a fragment of a chamfered stone likely to have come from a window embrasure, whittle-tang bladed knives, metal artefacts including a stick pin, a copper alloy annular brooch fragment with incised decoration, a copper alloy book clasp, a copper alloy rim of a vessel, some late medieval and post-medieval pottery fragments, glass fragments, a late 15^th-century Edward VI silver penny minted in Dublin, three 17th-century halfpenny coins and a small number of wooden artefacts, notably a vessel lid or base. One of the most unusual finds was a 16^th/early 17^th-century copper alloy ring-dial, a type of astronomical instrument used to tell the time and date. A large quantity of butchered and burnt animal bone was recovered during the excavation of Site 3.

Site 6 comprised a double-ditched field boundary in Carrick townland, which was early modern in date.

Collectively, the archaeological works carried out at Yellow River Wind Farm have resulted in the identification of previously unknown archaeological sites which provide evidence for domestic, industrial, agricultural and funerary archaeological activity extending from at least the Early Bronze Age to the post-medieval period. Post-excavation analysis is ongoing and samples, including dating samples, have been sent to the relevant specialists. A preliminary report on the monitoring and excavations at Yellow River has been submitted to the National Monuments Service, and it is hoped that the final report, due in early 2026, will present a comprehensive account of the results of the archaeological excavations.