Centre of island identified by Ordnance Survey Ireland

The exact geographical centre of Ireland has been determined scientifically and officially by Ordnance Survey Ireland (OSi): it is near Castletown Geoghegan, and 5km from the Hill of Uisneach.

"It sits within a National Monuments Zone, on the location of an ancient graveyard and near the remains of Kilbride Church," says OSi, which clarified that it had analysed the centre of the island of Ireland.

The announcement came on Friday, and the determination was made after a request was lodged with Ordnance Survey by Ian Rowlands, formerly resident in Moate.

The OSi itself acknowledged there were many claims for the centre of Ireland, including in the Catstone, on the side of the Hill of Uisneach, a location in the Hill of Berries, and townland of Carnagh East, both in Roscommon as well as Hodson’s Pillar in Hodson Bay, near Athlone.

"I was personally hoping it would be nearer to Moate but at least it’s in Westmeath!" said Ian this week, adding that there have been various locations claiming the ‘centre’ title over the years – some as far west as Roscommon.

Ian had been involved in what he describes as "a personal project" in trying to verify the exact geographical centre.

"I was unable to establish, however, if any of these locations had been scientifically verified using the more up to date technology which is currently available.

"I contacted the Irish government mapping agency Ordnance Survey Ireland, who kindly responded to my enquiry and request to investigate and verify the exact location of the geographical centre of Ireland.

In November – prior to last Friday’s announcement – the Ordnance Survey notified Ian where they had determined the centre to be, and he was thrilled to be the first to visit the spot.

"The really interesting feature of this new location is that it falls directly on what appears to be a raised, man-made mound and marked on an old OS map as an ecclesiastical site," says Ian.

"Given that the location is also enclosed by a large boundary wall, it is in my amateur opinion that it is a possible settlement of unknown identity and age (but possibly Norman or even pre Norman)," says Ian.

The new calculation by Ordnance Survey Ireland (Osi), places the centre of the island of Ireland at the Irish Transverse Mercator (ITM) coordinates 633015.166477, 744493.046768.

"The calculation to find the exact geographic centre of Ireland was carried out by OSi using the most up-to-date, openly available geospatial data and widely used geographic information system (GIS) technology.

But, the organisation says, while it was easy to make the calculation, a decision had to be made on some variables: "Most notably, for this exercise, OSi took the conscious decision to exclude the 8,000+ islands and outcrops that encircle the island of Ireland. If these had been included, this additional data would have affected the shape from which the centre-point was calculated and would inevitably have delivered a slightly different result.

"Equally, if the calculation had been based on alternative boundary datasets (with more or fewer points to calculate from along the coastline, for example) the result could also have been different."

The organisation goes on to caution that if this exercise is repeated in the future, following erosion and sea level rises, the centre-point could shift again.

"Different data processing techniques could also generate different outputs. A previous study carried out by OSi more than 10 years ago, using a different methodology, sited the centre of Ireland 35km away from Kilbride Church, on the western shore of Lough Ree, opposite the Cribby Islands. In another 10 years’ time, advanced technology may tell another story. Perhaps the centre of Ireland could be the Hill of Uisneach after all?"

Of the site now ranked as Ireland’s centre point, the Osi, says the ancient graveyard near the remains of Kilbride Church was surveyed by the Archaeological Survey of Ireland in 1980: "The graveyard today comprises an oval area divided into irregular enclosures and is bordered by the remains of an earth bank and stones. The church is visible on the first edition of the OS six-inch map from 1837-1842 showing as a rectangular structure with a small transept projecting from the centre of the north wall."

Some geographers also believe the country’s marine territory should be included in any calculation and that the centre of Ireland varies with the tides.

Read the OSI report at: osi.ie/blog/where-is-the-centre-of-ireland/