Non-invasive Archaeological Research

Tionscadal Seandálaíocht Neamh-ionrach


The Longford Heritage Office, funded by the Heritage Council, aims to undertake research projects to survey elements of Longford's archaeological heritage using non-invasive and non-destructive techniques. These geophysical techniques include high-resolution aerial surveys, and below-ground surveys using electrical and magnetic resistance. The purpose of these projects was to provide us scientific data and information about the historical construction and extent of our archaeological monuments.



Cistercian Monasteries / Mainistreacha Cistéirseacha

In 2015, the same team turned its attention to monastic settlements in the county, specifically the Cistercian Abbeys at Abbeylara and Abbeyshrule, again to determine if circumstances of foundation and location had any effect on the development of these sites. Augustinian houses at Saints Island and Abbeyderg were also reviewed as a comparison.

Non-invasive archaeological survey of selected Anglo-Norman motte and bailey castles in Co. Longford

In 2012, a team from the National University of Ireland Galway (NUIG), led by Dr. Kieran O'Conor with Dr. Paul Naessens, looked at a selection of Anglo-Norman motte and bailey castle sites in the county. The purpose was to determine the influence - if any - being a frontier location at the edge of the Anglo-Norman occupation had on the construction of castles in Longford. A series of non-invasive surveys, including aerial photographic surveys, and physical investigation techniques that could look into the soil without disturbance, were carried out on these castle sites. The survey gave us a fascinating insight into the development of these medieval castles.  

Click here to download the project report.

Where was the other 'lost town' of Granard 

The development of the town of Granard, in the north-east of County Longford is interesting. Prior to the current town, there was an ancient Gaelic settlement, nearby in the townland of Granardkille. Then, around the year 1199 the lands in this area were granted to the Norman lord, Richard de Tuite, who was part of the Earl of Pembroke's, (often known in Ireland as 'Strongbow') forces, invited to Ireland by Diarmait Mac Murchada the embattled King of Leinster. 

Richard de Tuite built his new fortified stronghold on the top of the hill at Granard, which had previously hosted ring forts and possibly even an inauguration site for the O'Farrell clan. This stronghold comprised a motte and bailey castle, the ruins of which remain to this day and are known as 'The Moat of Granard'. At the base of this castle, a new Anglo-Norman town was established. However, this town was sacked and burned by Edward Bruce, brother of the then King of the Scots, Robert the Bruce. Local folklore states that this town was in a different location to the current town, believed to be on the northern side of the castle, along the roadway to Granardkille with its Early Irish church. This was supported by the fact that the main entrance into the castle defences appears to be from the north. 

To investigate this further, the Granard Motte Enterprise CLG partnered with the Longford Heritage Office to undertake non-invasive aerial and geophysical ground-penetrating surveys to see if there was any evidence of the medieval town in this location. Dr Kieran O'Connor and Dr Paul Naessens from the National University of Ireland Galway (NUIG) were brought on board to undertake the survey, with Target Archaeological Geophysics GSV. 

Interestingly, while a number of interesting potential archaeological features were discovered to the east of the castle, the main survey fields showed very little evidence of archaeological disturbance at all. However, absence of evidence is not evidence of absence, and future investigations may reveal more information in another location. 

Click on the link below to read the survey report