2005:315 - BALLAGHDERG, Donegal

An excavation was carried out at the site of a levelled ringfort at Ballaghderg, Co. Donegal, in advance of a proposed road realignment (N56 Mountaintop–Illistrin) outside Letterkenny. The Archaeological Survey of County Donegal (Lacey 1983, 198) noted that the site was no longer visible aboveground, although it was extant when the OS first surveyed the area in 1835. Road improvements in the mid-19th century caused partial, though substantial, destruction and the monument was not included on the third-edition map (1905). Ploughing, land improvements and prolonged soil creep had removed any surface indication of the site, which was situated on a west-facing hill slope with commanding views to the north and north-west. Following a site inspection, the extent of the ringfort was delimited as a curving line of mature ash trees on the western side of the N56, despite much of the area having been reclaimed through the dumping of construction waste. The modern N56 from Letterkenny to Dunfanaghy preserves the most direct route from the early medieval monastic site of Kilmacrenan to those at Raphoe and Derry, through a natural pass in the highlands north-west of Letterkenny.

The site was separated into two areas of excavation on either side of the N56. Area 1 measured c. 50m north–south by 8m and was the subject of testing by Angus Stephenson in 2002 (Excavations 2002, No. 430, 02E1629–31). Area 2 was identified during the excavation phase as a curving line of mature trees flanking a shallow depression on the west side of the N56. An area c. 20m by 10m was stripped of topsoil and reclamation deposits, revealing archaeological stratigraphy at a depth of 2m below present ground level.

The principal feature within Area 1 was a short length of ditch cut into natural subsoil to a depth of 1.1–1.4m. It extended beyond both the eastern and western limits of excavation and measured 3–3.5m wide. On the northern side the cut was defined by a sharp break of slope and steep sides leading to an occasionally concave but generally flat base. The southern side was less straightforward, where a small step was apparently incorporated. The southern side was truncated by a later soakaway. The ditch at this location contained a clear-cut stratigraphic sequence, beginning with an accumulation of basal silt, followed by a build-up of occupational debris that contained occasional flecks of unidentified animal bone, moderate charcoal inclusions (exclusively willow, with a single example of oak), charred hazelnut shells (Corylus avellana L.), charred bark and a possible charred pronotum of a weevil (Curculionidae sp. indet.). Two charred caryopses of a representative of the grass family (Poaceae) were too poorly preserved for further identification. Charcoal from this occupation deposit was dated to the period AD 690–900. These lower deposits were sealed by a slipped internal bank deposit and subsequently by alternating clay and silt layers.

Evidence of the inner bank remained well beneath ground level as a small mound of reddish-orange redeposited subsoil, which survived to a height of 0.25m, upcast from the excavation of the ditch. It was a maximum of 5m wide at the base, although this may be due in part to slip on both sides. Other features in this area included shallow drains and a possible post-hole located beyond the enclosing ditch.

The enclosing ditch was seen to continue into Area 2 from Area 1 and extend to the north-east into a neighbouring plot. There were no other archaeological features recorded. The topography of the site in Area 2 necessitated a change in ditch morphology. The excavated material probably formed a bank at the top of a natural scarp. It appeared that the original site was situated on a small plateau overlooking a river valley. At 0.4m deep, the cut was not as deep as Area 1; its location at the base of a natural scarp enhanced its defensive properties. Four deposits were recorded within the cut but contained no environmental or cultural material.

Reference
Lacey, B. 1983 Archaeological Survey of County Donegal. Donegal County Council, Lifford.

Unit 21, Boyne Business Park, Greenhills, Drogheda, Co. Louth