Archaeological Project Design
Ballylongford Non-Intrusive Archaeological Survey and Landscape Assessment
Prepared by Ethos Heritage CIC Diarmaid Walshe BBs Hons, PCGE, MA Arch Rianca Vogel BSc Arch, MA
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Table of Contents
Contents
1. Project Overview................................................................................................................3 2. Archaeological and Historical Background.........................................................................3 2.1 Carrigafoyle Castle.......................................................................................................3 2.2 Carrig Island Religious Settlement................................................................................5 2.3 Corran Point Battery.....................................................................................................5 2.4 Lislaughtin Abbey......................................................................................................... 7 3. Research Framework.........................................................................................................9 3.1 Core Research Questions.............................................................................................9 4. Project Aims and Objectives..............................................................................................9 4.1 Overall Aim................................................................................................................... 9 4.2 Specific Objectives........................................................................................................9 5. Methodology.................................................................................................................... 10 5.1 Desk Based Assessment............................................................................................10 5.2 Drone Photogrammetry & DEMs.................................................................................10 5.3 Earthwork & Architectural Recording..........................................................................10 5.4 Geophysical Survey....................................................................................................10 5.5 Data Integration.......................................................................................................... 10 6. Site-specific Work Packages............................................................................................10 6.1 Carrigafoyle Castle & Siege Landscape......................................................................11 6.2 Carrig Island Religious Settlement & Corran Point Battery.........................................11 6.3 Lislaughtin Abbey & Harbour Fields............................................................................11 7.1 Hazards...................................................................................................................... 11 7.2 Site Impacts................................................................................................................ 11 7.3 Adaptation Measures..................................................................................................12 8. Community Training and Capacity Building......................................................................12 8.1 Purpose of Training.....................................................................................................12 8.2 Training Modules........................................................................................................ 12 9. Data Management and Deliverables................................................................................13 9.1 Primary Outputs.......................................................................................................... 13 9.2 Standards and Archiving.............................................................................................13 10. Permissions, Stakeholders and Logistics.......................................................................13 11. Programme and Sequencing..........................................................................................13
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1. Project Overview
This project proposes a targeted, nonintrusive archaeological survey of the Ballylongford (Map 1) heritage landscape, focusing on the following: The land across from Carrigafoyle Castle, Carrig Island (religious and civic settlement and Corran Point battery) The land around Lislaughtin Abbey, with a dedicated workstream to locate and map the historic harbour around Lislaughtin. (Map 1: Ballylongford (red dot)
The programme integrates desk-based map regression, earthwork and architectural recording, drone photogrammetry/Digital Elevation Models (DEMs), magnetometry, and electrical resistivity. The project aims to record standing fabric and buried remains, reconstruct the 1580 siege, fully map the Corran Point battery, characterise monastic and funerary sequences, and deliver conservation, monitoring and interpretation outputs.
2. Archaeological and Historical Background 2.1 Carrigafoyle Castle Carrigafoyle Castle (Image 1) is a late 15th century tower house built to command the Shannon Estuary. Its position on a rocky outcrop provided both defence and control over maritime movement. it features a spiral staircase of 104 steps that visitors can climb today.[9] The castle, now a listed National Monument, stands 100 feet (almost 30 m) high, and its battlements provide views of the estuary and the monastic Scattery Island in County Clare. The O'Connors of Kerry held political sway from this strategic base, allowing them to "inspect" ships passing to and from the port of Limerick. Thus, "taxation" and smuggling were the main sources of income. Image 1: Carraighfoyle Castle
The castle is most notable for its dramatic Easter 1580 siege during the Second Desmond Rebellion, when heavy cannonade and coordinated shipborne and shorebased artillery caused the collapse of the west wall.
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The castle was defended by a garrison composed of some 70 Irish, Italian and Spanish troops led by Captain Julian, an Italian. The Siege of Carrigafoyle Castle by Elizabethan forces under Lord Justice Sir William Pelham began on Palm Sunday (Image 2). After two days, it was breached by cannon fire and taken, following which the surviving defenders were all hanged. The cannon breach remains visible to this day.
Image 2: engraving of the 1580 siege of Carraighfoyle Castle. Pacata Hibernia 1633, Public Domain.
Towards the end of the Nine Years War, taking advantage of the distraction of the English, Chieftain John O'Connor briefly re-occupied the castle only to be put out again in 1603 by George Carew, the Governor of Munster. King James I restored the castle to the O'Connors in 1607, but in 1651 during the Cromwellian conquest of Ireland, it was again captured, this time by Cromwellian forces under Edmund Ludlow. Ludlow was Henry Ireton's second in command and, after Ireton's death, commander in chief in Ireland. Ludlow ensured the castle could never again be fortified and garrisoned by knocking the outer defensive walls. The background to the actual siege and its conduct is unknown and only archelogy may be able to fill in the blanks.
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Archaeological significance includes:
Foreshore deposits containing artillery impact debris Collapse material from the breached west wall Potential landing places and approach routes Possible survival of siege works and camps from both sieges
The castle is vulnerable to coastal erosion and rising sea levels, including undercutting of the castle rock and bawn foundations.
2.2 Carrig Island Religious Settlement Carrig Island contains a multiperiod ecclesiastical landscape, beginning with an early Christian monastic enclosure (lios) and continuing into the medieval period with a church, burial grounds, and a holy well. The religious sites on the island date from the sixth century including an early Christian church and settlement that was connected with the major monastery of St Senan on Scattery Island (almost opposite on the Clare coast of the Shannon), stood within the lios or large circular earthenwork enclosure. The traces of various buildings on the ground are clearly visible from the air, and also in times of drought. Within the site is a well known traditionally as the Friars’ Holy Well. The remains of a stone church (Image 3), nave, tower, staircase, chancel and sanctuary dating from the medieval period, possibly 13th century, are still standing, and suggest that the building was once a very impressive structure. Following the reform of the Irish Church in the early 12th century, this establishment, like its mother-house on Scattery Island, was occupied by the Canons Regular of St. Augustine until 1580 Image 3: Carrigh Island Church circa 13th Century
The site has the potential to includes early medieval enclosure elements, unrecorded graves, and potential waterlogged deposits near the holy well.
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Image 4: Crop marks (orange arrows) Church marked by blue arrow
The air photo of Carrigh Island (Image 4) clearly shows a large circular cropmark surrounding the church, highlighted by the blue arrow, positioned at the centre of this enclosure. Within the cropmark, the outlines of former buildings and houses are visible, indicating past settlement activity. A distinct road can be seen running outward from the enclosure, along with several additional features marked by the orange arrows, all of which help to illustrate the complexity of the historic landscape preserved in the cropmarks Later Napoleonic era military construction may overlie parts of the ecclesiastical complex, creating a layered archaeological landscape that needs to be invistaged.
2.3 Corran Point Battery The Corran Point battery is a rare surviving early 19 th century coastal defence work forming part of the Shannon Estuary’s Napoleonic era fortifications. It includes a gun platform, parapet embrasures, bombproof magazine, and Blockhouse. This battery commanded the southern part of the channel between Carrig Island and Scattery Island (Map 2), a distance of about two miles, so that the passage of the river here was commanded by the two batteries. The main building, the Blockhouse of the battery was constructed of dressed stone remains. The North side measures 16.3m in length, it displays a semi-circular headed dressed doorway which has two pulleys attached, possibly to draw up the door. It also displays four small rectangular windows which measures 0.9m in length. 6
The south side has no windows or doorway but, in the interior, running along the wall from the first floor to the roof is a stairway. The eastern side measures 9.85m in length and displays one large window and two small rectangular ones. The western side also has one large window and four small rectangular ones. The moat and ramparts of the battery have almost disappeared, the removal of the stonework causing the gradual collapse of the scarp and counterscarp. The Blochhouse remains, the doorway having been altered and extended in recent years to form an opening at ground level.
Map 2: Map of the battery - 1914-15 editions of the OS maps
The gun platform within the Blockhouse is at roof level with its positions for two howitzers is approached from the upper floor level by a staircase built within the wall thickness. The gun parapet which lies in front of the Blochhouse held firing positions for 6 24 pounders guns. The inner face of the parapet and the banquette are constructed of regular ashlar masonry, the banquette having a shallow groove in the stonework for the iron rail of the traversing mount for each gun. The Blockhouse (Image 5) has the usual battered-wall surfaces, constructed of squared rubble built to courses with regular masonry at the quoins and at the door, window and musket-loop openings. This fortification would have accomdated 20 men and their equipement. In 1889, the artillery garrison was withdrawn and the guns were dismantled.
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Image 5: Air view of the battery clearly showing the Blockhouse and the 2 gun positions on the roof
Archaeological value includes: Survival of rare key defensive architectural elements Potential to reconstruct firing arcs and defensive strategy Evidence of disturbance to earlier monastic deposits
The site is exposed to wave action, with risks such as scour at the gun emplacement and the effect of rising sea levels.
2.4 Lislaughtin Abbey Lislaughtin Abbey is a late 15 th century Franciscan friary with substantial Gothic fabric and an associated graveyard. Lislaughtin Abbey (Image 6) is a Franciscan friary, just over 1km from Ballylongford, in the diocese of Ardfert and Aghadoe. It was built by John O’Connor Kerry, Lord of Kerry, in 1470 on possibly an earlier church dedicated to St Lachtín who died in 622 AD. (Image 5)
Image 6: Lislaughtin Abbey
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The abbey was the resting place for John O’Connor Kerry in 1485 and his kinsmen, as well as Thomas Fitzgerald, heir of the Knight of the Glin, executed in 1567. After John O’Connor Kerry abdicated his position in favour of his son and heir, Cornelius, John and his wife Margaret Nagle retired to the friary. Cornelius O’Connor Kerry, had a silver processional cross commissioned in 1479 and is held in the National Museum of Ireland.The gothic inscription reads: “Cornelius son of John O’Connor, head of his sept and Eibhlm, daughter of the Knight, caused me to be made at the hands of William O’Connor, A.D. 1479.” Lislaughtin Abbey is a long house divided into a choir and nave. A tower, long since gone, located over the choir was a four storey 60ft tall structure. The choir, between the nave and the sanctuary, was an area for seating the clergy and choir, and was lit by a window in the east wall. This window is divided into four by stone mullions and surmounted by bar tracery. The south wall of the choir has three windows divided in two by stone mullions. All the windows are from cut limestone and all are pointed. Along the south wall of the choir is a tripe sedilia, seating for the clergy, in stone. The north wall of the choir has a doorway that leads to the refectory on the ground floor and dormitory above. This building has 30 windows, and northeast of it a two-storey structure housed the friary’s garderobe. The nave, the central part of the building to accommodate the congregation, has two entry points. On the west gable lies the main entrance. It is formed from cut limestone and is almost 2m high. Over the doorway is a pointed window, originally a twin-lighted window. The second entry point is on south wall, 1.7m tall and of cut limestone. The nave’s interior has two tomb niches with ogee-form hoods and pinnacles in the north wall.
Image 7: Air view of the abbey, possible harbour and features in the surround fields
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Documentary, air photos and cartographic evidence strongly indicates a harbour (Image 7) in the surrounding fields, including quay revetments, slipways, compacted harbour surfaces, and trackways linking the abbey to the creek (Image 6) The site is vulnerable to waterlogging and erosion of estuary facing features, harbour structures and loss of archelogy caused by rising sea levels.
3. Research Framework 3.1 Core Research Questions 1. Where were the English siege batteries and naval positions in 1580, as described in the English State Papers’ account of the engagement, and how are their effects preserved? 2. How did the Corran Point battery reuse or disturb earlier ecclesiastical features? What features lie buried on the site? 3. What is the spatial and chronological organisation of the Carrig Island religious/civic settlement and Lislaughtin Abbey? 4. How will projected coastal change affect the survival of these features?
4. Project Aims and Objectives 4.1 Overall Aim To produce an integrated archaeological, architectural, and environmental dataset for statutory management, conservation planning, and public interpretation.
4.2 Specific Objectives
Reconstruct the 1580 siege landscape and what features survive. Establish the firing lines, gun emplacements and military camp of the English forces Define the ecclesiastical and civic settlement footprint on Carrig Island Map the Corran Point battery in full. Possible clean back of the gun emplacements Locate and characterise the possible presence Lislaughtin Abbey harbour and the surrounding earthworks, trackways and buried archaeology Establish a climate change monitoring baseline Produce a Geographic Information Systems (GIS) integrated dataset for long-term management
5. Methodology 5.1 Desk Based Assessment
Map regression to reconstruct historic shorelines and harbour positions 10
Collation of siege accounts, Admiralty plans, estate maps, War office records of the Battery and aerial imagery Tidal planning and access logistics
5.2 Drone Photogrammetry & DEMs
High resolution Ortho mosaics Micro topographic DEMs for inundation modelling Multitemporal datasets for annual and post storm comparison
5.3 Earthwork & Architectural Recording
Measured plans and elevations of church on the island, the Battery, and associated structures Condition scoring and masonry assessment of the Battery and church remains on the Island Recording of earthwork and upstanding features
5.4 Geophysical Survey The island presents an exceptional opportunity for a comprehensive archaeological geophysical survey, particularly around the early ecclesiastical site arounding the surviving remains of the Church and the surrounding landscape where notable cropmarks have appeared in aerial photography since 2014. These anomalies strongly suggest the presence of subsurface structural features, enclosures, and possible settlement activity that have never been systematically mapped. Importantly, the proposed investigations will be entirely non-intrusive and will not involve any excavation. By relying solely on geophysical techniques such as magnetometry, ground-penetrating radar, and resistivity we can obtain high-resolution data while ensuring that the unique archaeological remains on the island remain undisturbed and fully preserved. This approach allows us to understand the extent, character, and significance of the buried features without impacting the integrity of the site, supporting both responsible heritage stewardship and future research. Magnetometry detects magnetic anomalies from fired features, hearths, and metal rich deposits, including artillery impact zones and occupation deposits. Electrical Resistivity maps buried masonry (high resistance) versus fills/ditches (low resistance), including magazine vaults, quay revetments, church foundations, and compacted harbour surfaces.
5.5 Data Integration
GIS integration of all spatial datasets. Within archaeology, GIS digitises, manages, and analyses spatial data to support interpretations
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of human behaviour and landscape change, while enabling 3D modelling, predictive site mapping, and environmental analysis DEMs differencing is applied to model erosion and inundation. DEMs represent three-dimensional bare-earth terrain surfaces derived from elevation data and are essential for surveying, mapping, and analysing archaeological sites and landscapes Interpretation of geophysical anomalies with map regression and measured plans
6. Site-specific Work Packages 6.1 Carrigafoyle Castle & Siege Landscape
Documentary collation of siege accounts and historic charts Low tide drone orthomosaic and DEM Magnetometry and Resistivity across the posable location of the English Siege positions (map in English State Papers) and surrounding landscape for the 1580 and 1649-1550 series. Resistivity over bawn and inner precinct (OPW permission required) LiDAR of the area of the fields around the site Outputs: artillery impact mapping, Site of camp, siege lines, gun pits, buried wall footings, risk assessment caused by modern occupation
6.2 Carrig Island Religious and Civic Settlement & Corran Point Battery
Collation of Admiralty plans and estate maps Island wide orthomosaic and DEM LiDAR for raised features Measured recording of gun platform, parapet, magazine entrances, and church fabric Study and assessment of Air Photos for cropmarks over different years Magnetometry across the island to record buried features especially around the church Resistivity across the island to record buried features over vaults, revetments, and church foundations Outputs: consolidated battery plan, plan of buried archaeological features, mapped relationship with ecclesiastical features
6.3 Lislaughtin Abbey & Harbour Fields
Map regression to identify quay lines and historic shoreline LiDAR to see raised features Drone DEM for inundation modelling Measured recording of Abbey surrounding landscape Resistivity across targeted field grids Magnetometry in the surrounding fields for ancillary economic features
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Outputs: mapped harbour footprint, field structures, buried archaeology, protection recommendations. Plan of the area around the Abbey structure
7. Climate Change Risk and Adaptation
7.1 Hazards
Rising sea levels Increased storm frequency Accelerated coastal erosion Saltwater ingress Higher groundwater tables
7.2 Site Impacts
Undercutting of castle rock and bawn foundations Wave scour at magazine areas and revetments Waterlogging and erosion of archaeological features, the island landscape and possible harbour structures
7.3 Adaptation Measures
Annual and post storm drone monitoring Condition scoring and risk indexing Preservation by record (possible excavation) for imminently threatened features
8. Community Training and Capacity Building 8.1 Purpose of Training To equip local community members, volunteers, and heritage groups with the skills and confidence to participate in archaeological recording, monitoring, and landscape stewardship.
8.2 Training Modules Module 1: Introduction to Archaeological Survey Understanding archaeological landscapes Reading earthworks and historic features Safe working practices on coastal and intertidal sites Module 2: Magnetometry Principles of magnetic survey Identifying fired features and metal rich deposits Hands on training with fluxgate gradiometers Grid setup, transect walking, and data logging Module 3: Electrical Resistivity
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Understanding soil resistance and buried masonry detection Setting up twin probe and multiprobe arrays Collecting and interpreting resistivity grids Identifying foundations, revetments, and harbour surfaces
Module 4: Drone Survey and Photogrammetry Drone safety and legal requirements. Flight planning for archaeological sites. Capturing orthophotos and DEMs. Introduction to photogrammetric processing and 3D modelling. Module 5: Total Station and GNSS Survey Setting up and operating total stations/Dumpy Levels Recording standing structures and earthworks Establishing control points and survey grids Exporting data for GIS integration 8.3 Training Outputs A trained local volunteer cohort capable of assisting with ongoing monitoring. Community generated datasets feeding into the project GIS Increased local stewardship and long-term engagement with the local heritage landscape Skills legacy supporting future heritage projects in the region
9. Data Management and Deliverables 9.1 Primary Outputs
GIS package with ortho-mosaics, DEMs, magnetics, resistivity, and interpreted layers Measured plans and elevations Consolidated Abbey and Carrgh Island field plan Condition and risk index Conservation action plan Monitoring protocol and emergency recording checklist
9.2 Standards and Archiving
All recording to Irish and European national heritage standards Geophysical data processed as plan view grids and interpreted anomaly maps Final datasets deposited with National Monuments Service and local archives.
10. Permissions, Stakeholders and Logistics
OPW and National Monuments Service consents 14
Coordination with National Museum of Ireland Archaeologlist Local stake holders’ involvement Landowner agreements Tidal planning and boat support Drone scheduling outside bird nesting windows Safety exclusion zones around unstable masonry
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11. Programme and Sequencing
Phase 1 — Desk Assessment & Permissions Map regression, documentary collation, tidal planning, stakeholder liaison Phase 2 — Baseline Recording Drone photogrammetry, DEMs, measured architectural recording, condition assessment Phase 3 — Geophysical Survey Magnetometry and resistivity across all targeted areas Phase 4 — Data Integration & Climate Risk Modelling GIS integration, DEM differencing, erosion mapping, condition scoring Phase 5 — Reporting & Management Outputs Technical report, conservation plan, monitoring protocol, public interpretation materials Ongoing Monitoring Annual drone surveys and post storm assessments
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