A PREVIOUSLY unrecorded “impressively large earthwork” – believed to be part of the outer defences of an early medieval royal stronghold at Knowth, in the Boyne Valley – has been identified by an archaeological survey.
The survey, commissioned by former attorney general John Rogers SC, has been submitted to An Bord Pleanála as additional information as part of its consideration of plans for an N2 bypass running east of Slane, Co Meath.
Carried out by archaeologists Joe Fenwick, Gerard Dowling and Roseanne Schot of the Brú na Bóinne Research Project, the survey found the earthwork at Crewbane, near the home of Mr Rogers, who is objecting to the bypass.
It was prompted by the discovery in 2007 of a souterrain in Crewbane, at the perimeter of the Brú na Bóinne Unesco world heritage site “buffer zone” 2km east of Slane village and 1km from the prehistoric passage tomb of Knowth.
“This impressively large earthwork is not recorded in the Sites and Monuments record for Co Meath,” the archaeologists say.
It presents a “massive facade” when approached uphill from the south, averaging 4m in height and extends over a distance of 23m.
“It is apparent that the Crewbane souterrain is not an isolated archaeological monument in the landscape, but one element in a complex of archaeological features situated on and around this prominent ridge overlooking the river Boyne.
“These include a second and possibly third potential souterrain, a substantial linear embankment, a circular enclosure [of] 40m in diameter [a possible ring fort], a relict field system and associated open settlement of possible medieval or early modern date . . . ”
They speculate that the complex “might have served as a defensive outpost protecting the western flanks of the royal stronghold at Knowth”, saying it was “unfortunate” that it straddles the western boundary of the Unesco world heritage site buffer zone.
“It is likely, however, that had this complex been known at the time the world heritage site perimeter was being drafted, its influence would have extended its perimeter somewhat further to the west and northwest,” Mr Fenwick has told An Bord Pleanála.
In a letter to the board, he acknowledged that an alternative route of the bypass running west of Slane would also have a large number of “significant impacts” on the archaeological, architectural and cultural heritage of the area, including Slane Castle demesne.
Mr Fenwick suggested that the “only realistic option” was to ban heavy goods vehicles entirely from the village and provide an east-west corridor to the north of Slane, to redirect this traffic towards “the new and underutilised” M1 and M3 motorways. The consultations end on Friday.