2003:362 - CAW, Derry

A proposed development of 160 houses on an area of land overlooking the River Foyle in the townland of Caw, Co. Derry, was found to be within the area of a battle reported in the Annals of the Four Masters for the year AD 1200 between the Cenél Eoghain and Cenél Conaill. Other than the battle site, there were no other known archaeological sites within the area of the development.

The development site is located on the eastern shore of the River Foyle, just south of the Foyle bridge access road. To the west of the site is the Gransha Intake, while the eastern and southern edges of the site are bounded by existing developments. The area of the development measured 12.5ha. The ground along the southern side is high and undulating and falls away quite sharply towards the north-west and the River Foyle. The northern half is, by contrast, quite low and relatively level. Running across the site from east to west is a large, deep drain with extensions running off it towards the southern boundary.

The development lay across an area of glacial sands and gravels that have been deposited on Dalradian metamorphic rocks. The steep slope which runs across the site, dividing the area into two distinct topographic zones, would appear to be the result of erosion and deposition of the nearby Foyle.

The area of water and reeds, noted on the OS as Gransha Intake, is the product of the construction of the Derry and Coleraine railway line in the 19th century. The first-edition OS 6-inch map of 1832 records the area as an extension of Rosses Bay, with a faint line probably indicating the extent of a mud bank. By 1856 and the OS second-edition map, the railway line has been constructed along this mud bank line, leaving a tidal lagoon between the railway and the shore. Much of the lower ground on the development would have been tidal until the construction of the railway line.

Due to the possibility of metalwork surviving from the reported battle, a metalwork survey of the site was undertaken. Four corridors, measuring 5m wide and varying in length from 175 to 225m, were laid out across the site and surveyed. Nothing from the reported battle was found, but a cluster of four 18th-century musket balls was recovered from the north-west corner of the site and may be the result of wildfowling along the tidal margins of the River Foyle. As a result of this survey it was decided by DoE:EHS that no further metal detecting was required and topsoil-stripping was allowed to proceed.

Topsoil-stripping commenced on 8 January 2003 using a mechanical digger fitted with a toothless bucket. Twelve areas of archaeological interest were uncovered, all located on the higher ground on the southern side of the development area. There were no archaeological deposits uncovered on the lower ground.

Area 1 was located on the south-east edge of the site. A group of four pits and two burnt areas were found spread over an area 14m north–south by 16m. No finds were recovered from any of the excavated features.

In Area 2, two pits, both with evidence for burning, were located, one of which was badly truncated by agricultural activity. Again no finds were recovered.

In Area 3, a small area with a long narrow pit and a single circular post-hole was uncovered. The pit, orientated east–west, measured 1.8m in length, 0.5m in width and 0.4m in depth. Nothing datable was recovered from the post-hole, although a quantity of iron slag was recovered from the pit and indicated the presence of ironworking on the site.

In Area 4, a Neolithic house was located close to the centre of the site of a small spur of higher ground that would have originally jutted into the tidal area of the bay. The structure, orientated north-west/south-east, measured 7.2m by 5m internally. Both the east and west walls of the house had been badly truncated by post-medieval boundary ditches and only short lengths of both survived, although in areas where undisturbed it appears that the wall slot was intermittent, with several clear gaps. The wall slot, where present, contained large packing stones, with evidence for post-holes in several places along its length, and a possible doorway located about halfway along the east wall.

Internally, only two features were found. A shallow circular pit containing a few sherds of pottery was located in the approximate centre of the house and may have acted as a roof support, although no trace of a post or any packing was evident. Another pit was located 0.8m north of the first pit. This pit contained no finds, but a thin layer of reddish burnt sand on the base indicates that it may have functioned as a hearth.

A charcoal sample from the northern wall slot has been dated to 3905–3707 cal. BC (one sigma, UB-4979). The small pottery assemblage of 25 sherds recovered from the house has been identified as Western Neolithic ware, with a date range of c. 4650–3650 BC.

Areas 5–10 and Area 12 were located running in a westerly direction across the high ground. They consist of isolated groups of pits and post-holes, none of which form part of a structure. Evidence indicative of ironworking has been found in all these areas, with a large amount of slag being recovered. Some of this slag has the characteristics of having formed on a furnace base, and the remains of two subsoil-cut bowl furnaces were excavated in Area 7. A charcoal sample from one of these furnaces, C161, has been dated to cal. AD 376–426 (one sigma, UB-4980), giving a Late Iron Age date for the ironworking on the site. Some of the slag would appear to have been deliberately cut, perhaps a result of attempts to separate the iron from slag after smelting. A few badly corroded iron nails have been recovered and it is possible that they were produced on-site, although they may represent later intrusions or stray finds. These are the only iron artefacts that have been found from an archaeological deposit on the site.

Area 11 was located on the highest area of the site, situated on a ridge on the extreme western edge of the site. In this area, four pits were found within an area of 8m north–south by 6m, while a further pit was located 12m south-east of these. The four pits all had the same fills but produced no artefacts, while the fifth, isolated, pit had a different fill and contained several sherds of Western Neolithic ware. The date of the four pits remains undetermined.

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