Between 2000 and 2003 archaeological excavations were carried out in advance of construction of the N4 Sligo Inner Relief Road. The excavations revealed evidence of settlement stretching back some 6,000 years into the Early Neolithic period. Sites discovered ranged from large ceremonial enclosures dating to the Neolithic and Bronze Ages, to settlement sites of houses and associated burials dating from the middle Bronze Age, through Iron Age settlement evidence, a medieval defended farmstead and post-medieval urban settlement.
The discoveries were very exciting and it is hoped will add significantly to the prehistory of Sligo. Results will be published in 2006.
Impact on this site in Tonafortes townland at the southern end of the scheme was kept to a minimum and only that portion of the 85m diameter enclosure impacted on directly by the scheme (c.10%) was investigated. The site was built between 2460 - 2140 BC, dates obtained from radiocarbon analysis of charcoal found within the ditch. It was up to 6m wide and 2m deep in places was dug leaving a causeway of unexcavated soil as the entrance into the enclosure’s arena. Classified as a henge monument, these monuments are commonly found associated with passage tombs and are thought to have been ritual centres dating to the Late Neolithic and early Bronze Age periods.
In a small valley in the townland of Caltragh, midway along the N4 route, a number of archaeological features dating to the Neolithic and Bronze Age were discovered spanning a period between c. 4000BC and 500BC.
A stone wall over 100m in length formed an arcing open enclosure facing onto an area of bog land, which would most likely have been open water at the time the wall was built. The discovery of a number of small, polished stone axes and some decorated animal bone within the fabric of the wall all suggest a Neolithic date between 4000BC and 2500BC.
A number of human cremation burials were discovered in the valley dating to around 1600BC. Two pits contained the cremated remains of an adult individual and analysis of the burnt bone from one has determined them to be probably those of a woman, who died aged probably between 40 and 50 years old buried with the remains of her stone bead necklace. Another large pit on the northern edge of the valley contained the cremated remains of a youth, probably between 13 and 16 years old at the time of his or her death.
Nearby were discovered three Bronze Age houses dating to the same period as the cremation burial, perhaps where those buried in the pits once lived. Pits had been dug along the interior walls of the buildings, found to contain a number of saddle querns, suggesting that they may have been used for storing grain. At the base of the valley two mounds of burnt stone were built up over the remains of the earlier Neolithic stone wall, dating to between 1700BC and 1350BC. Representing the remains of cooking or industrial activity, in total eight of these fulachta fiadh, or ancient cooking places, were discovered on the old Caltragh lake edges, dating from between 2500BC to 800BC.
Built between 4,000BC and 3,800BC, and centred on the summit of a large elongated ridge. a huge enclosure was delineated at its northern and southern sides by the remains of a palisade trench with packing stones which once supported the upright posts. These were once set into it and would have formed a fence between 1.5m and 2m in height. Outside of the fence line were a series of ditches separated by gaps, or causeways of undug soil.
This type of enclosure is found in Britain and on Continental Europe but the discovery of such a causewayed enclosure along the N4 adds to a very short list of this site type in Ireland. No universal explanation has been accepted for their function and it is felt by many archaeologists that they were places of ceremonial or ritual activity, while others propose that some enclosures were perhaps cattle marts and/or the meeting places of a scattered community.
The ditches were rich in artefacts dating from the early Neolithic period: flint arrowheads, pottery, a deposition of quartz crystals, as well as a broken porcellanite axe. Between 40 and 50 pits found and excavated within the enclosure produced more artefacts dating from the Early Neolithic, including flint tools such as blades and scrapers, and pottery.
Iron Age activity was also present, shown by a small, circular structure, radiocarbon dated to between 370 cal BC - 30 cal BC discovered on the more western part of the ridge.
A medieval ringfort was discovered close to the highest part of the ridge. Taking advantage of the defensive and commanding position, the 40m diameter ditched enclosure was built between cal AD 570 and cal AD 880 and served as a defended farmstead during that period.