462 NMS sites 334 within protection zone 157 listed buildings 8 of 9 archaeological periods

Arklow is a barony of County Wicklow, in the historical province of Leinster (Irish: An tInbhear Mór), covering 272 km² of land. The barony records 462 NMS archaeological sites and 157 NIAH listed buildings, placing it at around the 42nd percentile among 280 ROI baronies for sites per km². This means it is in the lower half of all baronies for sites per km². Dated archaeological evidence runs from the Mesolithic through to the Modern, spanning 8 of 9 archaeological periods, placing the barony in the 86th percentile among 280 ROI baronies for chronological depth. This means it is in the top fifth of all baronies for chronological depth. The largest dated subset of recorded sites dates to the Iron Age. Logainm flags 57 placenames in the barony as carrying a recognised heritage root; the largest share — around 84% — are names associated with early Christian church and monastic foundations.

Detailed boundary map of ARKLOW barony, WICKLOW
Arklow boundary detail
Regional context map showing ARKLOW barony within WICKLOW
Arklow in regional context

Heritage at a glance

Percentile rankings throughout this profile compare each barony only against the other 279 Republic of Ireland baronies.

462
Recorded NMS sites
42nd percentile
334
Within protection zone
72.3% of recorded sites
157
NIAH listed buildings
69th percentile
272 km²
Barony area

The recorded heritage of Arklow

The National Monuments Service Sites and Monuments Record (SMR) is the statutory inventory of archaeological sites for the Republic of Ireland, maintained by the Department of Tourism, Culture, Arts, Gaeltacht, Sport and Media. Sites recorded here include earthworks, ringforts, megalithic tombs, ecclesiastical remains, and post-medieval features; not every record is legally protected, but each is registered as a monument of archaeological interest.

The National Monuments Service records 462 archaeological sites in Arklow, putting it at the 42nd percentile among 280 ROI baronies for sites per km². This means it is in the lower half of all baronies for sites per km². Of these, 334 (72%) fall within a recorded monument protection zone. The record is dominated by defensive sites — ringforts, enclosures, hillforts, and stone forts (123 sites, 27% of the total), with ecclesiastical sites forming a substantial secondary presence (105 sites, 23%). The most diagnostically specific type is Burnt mound (40 records, 9% of the barony's NMS total) — compared to an ROI average of 2% across all baronies where this type occurs. Burnt mound is a heap of fire-cracked stone, ash and charcoal, with no surviving trough, dated Bronze Age to early medieval. The broader 'Enclosure' classification — which catches unclassified ringforts and field enclosures — accounts for a further 76 records (16%) and reflects the difficulty of sub-classifying degraded earthworks from surface evidence alone. Across the barony's 272 km², this gives a recorded density of 1.70 sites per km².

Most common monument types

Hover or tap a monument type to see its definition.

TypeCount
Enclosure a banked or ditched feature of uncertain type, used as a catch-all where the original function cannot be determined from surface evidence 76
Burnt mound a heap of fire-cracked stone, ash and charcoal, with no surviving trough, dated Bronze Age to early medieval 40
Church a building used for public Christian worship, of any date from c. 500 AD onwards 35
Graveyard a burial area associated with a church, in use from the medieval period onwards 32
Ringfort – rath an earthen ringfort enclosed by a bank and external ditch — the most common Early Medieval farmstead, broadly dated 500–1000 AD 30
Ritual site – holy well a well or spring traditionally associated with a saint, often credited with healing properties; many trace earlier ritual origins but devotion is documented from the medieval period onwards 17
Rock art geometric and other motifs carved on earthfast boulders or rock outcrops, mainly Bronze Age but with possible Neolithic origins 17
Pit a circular or sub-circular cropmark, soil-mark or excavated cavity, of any date from prehistory onwards 17

Chronological distribution

The dated archaeological record for Arklow spans from the Mesolithic through to the Modern, with activity attested across 8 of 9 archaeological periods. This is the 86th percentile across ROI baronies for chronological depth — an above-average span. The record is near-continuous, with only the Post Medieval period falling inside the span without any recorded sites. Activity concentrates most heavily in the Iron Age (127 sites, 38% of dated material), with the Early Medieval forming a secondary peak (75 sites, 23%). A further 132 recorded sites (29% of the overall NMS register for the barony) carry no period attribution — appearing as 'Unknown' in the bar chart below. This typically reflects either records that pre-date the standardised period vocabulary or sites awaiting specialist dating review, rather than a genuine absence of chronological evidence.

Mesolithic
4
Neolithic
9
Early Bronze Age
36
Middle Late Bronze Age
62
Iron Age
127
Early Medieval
75
Medieval
16
Post Medieval
0
Modern
1
Unknown
132

Sample of recorded monuments

Show 25 sample monuments (of 462 total)

A representative sample of 25 recorded monuments drawn from the barony’s 462 total NMS entries. Sites within a recorded monument protection zone and rarer site types are prioritised so the list shows a meaningful cross-section rather than only the most common type. Each entry shows the official Sites and Monuments Record reference number and the description published by the National Monuments Service.

Souterrain

SMR WI025-015—-Dunbur Headearly_medievalProtected

Probably natural sea caves, but adjacent to a church (WI025-017001-), and possibly used as souterrains while the ecclesiastical site was in use.

The above description is derived from the published 'Archaeological…

Rock shelter

SMR WI025-037—-Dunbur HeadProtected

Two caves excavated into the southern wall of a trench running across the neck of Bride's Head. A large quantity of broken flint was found in one of the caves (Martin 1932-3, 58); Martin likened them to flints found on…

Cave

SMR WI025-038—-Dunbur HeadProtected

Two caves excavated into the southern wall of a trench running across the neck of Bride's Head. A large quantity of broken flint was found in one of the caves (Martin 1932-3, 58); Martin likened them to flints found on…

Gateway

SMR WI031-002001-Ballynagran (Arklow By., Glenealy Ed)Protected

Situated within a moated site (WI031-002002-) on the summit of a low gently slopped hill with extensive views especially to the S. The remains consist of a vaulted gateway aligned NNE-SSW (L 6.65m; Wth 3.7m),…

Ecclesiastical site

SMR WI031-007—-Kilpoole UpperProtected

Situated on level ground with gentle E-facing slopes above and below the site. Traditionally the site of a monastic foundation associated with the Welsh saint Pol (Paul) and later belonging to the Templars and…

Cist

SMR WI035-041—-Knockanree LowerProtected

Situated on level ground towards the SW end of a low ridge. Small cist (dims. c. 0.43m x 0.3m) of four slabs with a capstone containing a food vessel, discovered in 1933. It was found in a rectangular enclosure marked…

Megalithic tomb – portal tomb

SMR WI036-008—-Brittas (Arklow By.)Protected

Situated on a marked NE-facing slope overlooking Potters River. The tomb consists of two portal stones, a backstone which leans markedly inwards and a displaced roofstone resting against the N portal-stone and…

Ogham stone

SMR WI036-010—-Castletimonearly_christianProtected

National Monument in state guardianship No. 304. Situated at the edge of the road on level ground overlooking the Potter's River valley. A large granite slab with its flat surface now uppermost (L. 1.48m; Wth 0.4-0.5m;…

Castle – unclassified

SMR WI040-005—-CastlemacadammedievalProtected

Situated on the NW edge of a spur of ground overlooking the Avoca River. Only one wall (L 5m; H 3m) of the castle survives, c. 80m SW of the 19th-century church (now abandoned). The castle stood within the medieval…

Mausoleum

SMR WI040-021004-Kilbride (Arklow By., Kilbride Ed)Protected

At the centre of a graveyard (WI040-021002-). A rectangular structure with a colonnaded façade on its N face and built into a low hillside at S. A partially legible inscription records its dedication, 'To the memory of…

Burial mound

SMR WI040-023—-Killahurler LowerProtected

Situated on a gentle N-facing slope. Steep-sided circular mound (diam. 16m; H 2.8-4m) defined by a fosse (Wth 2-4m; D 0.4m). Part of the centre and the E side have been removed through quarrying. An urn was allegedly…

Historic town

SMR WI040-029—-ArklowProtected

In 1571 the Manor of Arklow and the 'burgesses of the Earl's town of Arcloe' were required to, 'have paid the yearly rent of 3s. 4d., and some of them paid but 6d. by the year, with bearing Irish exactions as 'conyve,'…

Religious house – Dominican friars

SMR WI040-029001-AbbeylandsProtected

Situated on level terrain on the S side of the town. The site of the Dominican friary founded in 1264 by Thomas Theobald FitzWalter. Portions of the church and claustral buildings survived into the mid-18th century…

Religious house – Cistercian monks

SMR WI040-029004-FerrybankProtected

Situated on low-lying marshy ground in Arklow Town. Probably the site of a Cistercian Abbey, granted by Theobold Walter to the Cistercians of Furness, but possibly only in existence for a short period (Gwynn and Hadcock…

Settlement deserted – medieval

SMR WI041-003—-BallyrichardProtected

Situated on a gentle SE-facing slope. Templerainy Church ruins (WI040-017001-) located 1.7km to SW and Kilpatrick Church (WI036-023—-) located 2.5km to N. An area (dims. c. 350m NE-SW; 200m NW-SE) containing a large…

Chapel

SMR WI045-005—-Rock BigProtected

Situated in modern Roadstone quarry on a marked NE-facing slope overlooking the seashore, 2.1km SSE of Arklow town. Two holy wells, Lady's Well (WI045-006—-) and St. Patrick's Well (WI045-007—–) lie 130m to the SSW…

Hillfort

SMR WI035-062—-Kilcasheliron_ageProtected

Visible on aerial photographs (Michael Moore, 6 July 2006). Not recorded on the 6-inch OS 1st. ed.(1841) map but shown as an oval field (est. diam. c. 200m NE-SW; c. 100m NW-SE) on the 1908 ed. Possibly a hillfort.
The…

Kiln

SMR WI031-073—-CoolbegProtected

Archaeological monitoring in 2006 uncovered three possible kilns here (Excavation Licence 04E1633 (Area 1)). They are preserved in situ. (O’Carroll 2009, 571)

Compiled by: Claire Breen

Date of upload: 17 January…

Bullaun stone (present location)

SMR WI036-082—-BallynacarrigProtected

A granite block (48cm x 52cm) with a circular bowl (diam. 27cm; max. D 10cm). The surface around the circumference of the bowl is defaced. Moved from the church site at Castletimon (see WI036-009005- for original…

Anomalous stone group

SMR WI035-070—-KilcashelProtected

Situated on a N-facing slope within a copse of conifers c. 9m up-slope from a farm track. The remains consist of a chamber-like feature defined by two orthostats on the N and two other possible orthostats on the S. The…

Architectural fragment

SMR WI040-011008-BallintempleProtected

Situated on gentle N-facing slope with the steep valley of the Aughrim River 370m to NE & E. Bride's Well (WI040-011001-) c. 110m to the NW. Cropmark of levelled ringfort (WI040-031—) in field to S. Levelled…

Cairn – burial cairn

SMR WI035-073—-Barranisky EastProtected

Situated atop high ground with panoramic views of the surrounding countryside. Ordnance Survey trigonomterical station marking spot height 894ft. lies 35m to NNW and hilltop enclosure (WI035-074—) 80m to N. …

Hilltop enclosure

SMR WI035-074—-Barranisky EastProtected

Possible hilltop enclosure (approx. diam. c. 100m N-S x -110m E-W) situated just off summit of hill on steep N facing slope with commanding views of the surrounding countryside. Ringfort (WI035-045—-) 120m to NNW,…

Field boundary

SMR WI035-075—-Barranisky East,GlenteigeProtected

Possible hilltop enclosure (WI035-074—-) and cairn (WI035-075) situated just off summit of hill with commanding views of the surrounding countryside. Possible prehistoric field walls running roughly E-W immediately S…

Enclosure

SMR WI045-014001-Ballynattin

Discovered in 1998 during archaeological monitoring of works associated with the IDA Industrial Park (Excavation Licence 98E0257). Excavation revealed a rectangular area (14m E-W x 8m) defined by a U-shaped trench (Wth…

Listed buildings

The National Inventory of Architectural Heritage (NIAH) is a state survey appraising buildings of architectural, historical, archaeological, artistic, cultural, scientific, social, or technical interest. Each surveyed structure receives a rating from International (the highest, for buildings of European importance) through National, Regional, Local, and Record-Only.

The NIAH records 157 listed buildings in Arklow (68th percentile across ROI baronies). The highest-graded structures include 2 of National significance. The Republic holds 937 National-graded buildings in total, so this barony accounts for around 0% of the national total. Construction dates concentrate most heavily in the Victorian (1830-1900) period. The most-recorded building type is house (96 examples, 61% of the listed stock).

Terrain and environment

Mean elevation across the barony is 101m — the 60th percentile among 280 ROI baronies for elevation. This means it is in the upper half of all baronies for elevation. Elevation matters for heritage because higher-altitude baronies typically favour defensive monuments — ringforts and hilltop forts placed on prominent ground — while lowland baronies are more likely to carry the dense settlement and church networks of intensive agricultural landscapes. The barony reaches 561m at its highest point — a vertical span of more than 460m within its boundary, indicating significant topographic diversity. Mean slope is 6.3° — the 88th percentile among 280 ROI baronies for slope. This means it is in the top fifth of all baronies for slope. This is consistently steep terrain by ROI standards, the kind of landscape that tends to preserve upstanding archaeological features well. Slope is a key control on both land use and archaeological preservation: steep ground resists ploughing and tends to preserve earthworks intact, while gentle slopes favour intensive cultivation that damages or destroys surface archaeology over time. Localised maximum slopes reach 17°, typical of stream-cut valleys, escarpments, or coastal bluffs within the wider landscape. The Topographic Wetness Index averages 9.7, the 12th percentile among 280 ROI baronies for wetness. This means it is in the bottom fifth of all baronies for wetness. This is well-drained ground by ROI standards — typical of upland or steeply-sloping country that sheds water rapidly. Drainage matters for heritage because poorly-drained ground preserves organic archaeology (wooden trackways, leather, textiles, and on rare occasions human remains) far better than free-draining soil; well-drained ground favours arable use but destroys organic material rapidly. The land-cover mosaic combines improved grassland (59%), woodland (24%), and arable farmland (13%), giving a mixed agricultural and semi-natural landscape. In overall character, this is steeply-sloping terrain at modest elevation, with land use dominated by improved grassland.

Terrain measurements

Mean elevation100.6 m
Max elevation561 m
Mean slope6.3°
Wetness index (TWI)9.66 12th pct
Grassland58.8%
Woodland24.4% 86th pct
Cropland13.4%
Urban land2.5% 82nd pct

Where this barony sits in the Republic of Ireland

Drainage
12th
Woodland
86th

Geology and preservation

Bedrock geology shapes the landscape long before any settlement begins — controlling soil drainage, agricultural potential, the survival of upstanding monuments, and the preservation of buried archaeology. The figures below come from the Geological Survey Ireland 1:100,000 bedrock map.

The bedrock underlying Arklow is predominantly slate, sandstone (56% of the barony by area), laid down during the Ordovician period (94% by area, around 485 to 444 million years ago). The single largest mapped unit is the Kilmacrea Formation (56% of the barony's bedrock). With 9 distinct rock types mapped, the barony sits in the top third of ROI baronies for geological diversity (88th percentile) — typically a sign of complex tectonic history or coastal mosaics of differing rock units.

Dominant geological periodOrdovician (94%)
Dominant rock typeSlate, Sandstone (56%)
Mapped formations20
Distinct rock types9 88th pct for diversity

Rock type composition

Slate, Sandstone
56%
Rhyolitic Volcanics
11%
Slate
10%
Silver-Grey Mica Schist
6%
Slates
5%

Largest mapped unit: Kilmacrea Formation (56% of the barony)

Placename evidence

Logainm records 57 heritage-diagnostic placenames for Arklow, drawn from townland and civil-parish names across the barony. The dominant stratum is Early Christian ecclesiastical — cill-, teampall-, and domhnach-prefixed names that record the dense network of early church foundations established between the fifth and tenth centuries. The leading diagnostic roots are cill- (39 — church), teampall- (7 — church), and dún- (5 — hilltop fort or promontory fort). This is above the ROI average of 30.7 heritage placenames per barony. Logainm records 309 placenames for Arklow (predominantly townland names). Of these, 57 (18%) carry one of the diagnostic Gaelic roots tracked above; the remainder draw on more generic landscape vocabulary that does not encode a heritage period.

Pre-Christian / Early Medieval Defensive

RootCountMeaning
dún-5hilltop or promontory fort
ráth-4earthen ringfort

Early Christian Ecclesiastical

RootCountMeaning
cill-39church (early)
teampall-7church (later medieval)
mainistir-1monastery
tobar-1holy well
Grounding History report mockup

Explore further

Grounding History: 10 Maps of Northern Ireland’s Past

If you’re interested in Irish heritage more widely, the companion report for Northern Ireland brings together the analysis of all 462 NI wards into one place through 10 high-quality maps — covering monument density, archaeological periods, placename heritage, terrain, wetland, and the historic landscape at first survey. Take a look.

About this profile

Click any section below to expand.

What is a barony?

A barony is a historic administrative unit in Ireland, broadly equivalent to an English hundred. The 280 baronies used here are from the OSi 2019 National Statutory Boundaries (generalised 20m), covering the 26 counties of the Republic of Ireland. Baronies derive from the Norman period, were formalised in the 17th century, and have not been redrawn for statistical purposes. They vary enormously in area, from compact urban baronies in Dublin to vast upland baronies in Connacht, and should not be compared by raw site count without accounting for area differences.

What counts as a site?

This profile combines three distinct heritage registers, each with its own definition of what constitutes a recordable site:

  • Archaeological sites (NMS). The National Monuments Service Sites and Monuments Record (SMR) catalogues every known archaeological monument or site of archaeological interest in the Republic, from prehistoric burial mounds and ringforts to medieval churches and post-medieval defensive works. Inclusion does not require legal protection — only that the site has been identified, surveyed, and assessed as having archaeological value. A separate subset of these sites lies within a recorded protection zone, which gives them statutory protection under the National Monuments Acts.
  • Listed buildings (NIAH). The National Inventory of Architectural Heritage records buildings of architectural, historical, archaeological, artistic, cultural, scientific, social, or technical interest. Each surveyed structure is appraised on a five-tier scale: International, National, Regional, Local, and Record-Only. The NIAH appraisal is informational rather than strictly statutory, but it underpins local-authority Record of Protected Structures (RPS) listings.
  • Heritage placenames (Logainm). Logainm is the authoritative database of Irish placenames maintained by the Placenames Branch. This profile applies a heritage-diagnostic classifier to the Irish-language form of each townland name, flagging roots that signal defensive sites (ráth-, lios-, dún-, caiseal-, cathair-), ecclesiastical foundations (cill-, teampall-, domhnach-, mainistir-), prehistoric burial-ritual features (tuaim-, carn-, leaba-), or Norse-contact settlement (gall-). Townlands without one of these diagnostic roots are not flagged here — they may still carry historical significance, but that significance is not encoded in the name itself.
Editorial principles

The narrative sections of this profile follow several explicit principles:

  • Evidential. Every claim about this barony’s heritage character is anchored in the underlying register data. Where a site count, a placename count, or a percentile rank is cited, it is computed from the source datasets at export time, not estimated.
  • Comparative. Counts and metrics are reported alongside their percentile rank against the other 279 ROI baronies. A barony with 50 ringforts in absolute terms could be unusually high or unusually low depending on its size and regional context; percentile ranking removes that ambiguity.
  • Transparent on limits. Where a register has known coverage gaps, survey biases, or data-quality issues that affect this barony’s figures, the profile flags them rather than presenting the numbers as definitive.
  • No interpretation beyond what the data supports. The narrative does not speculate about historical events, social dynamics, or cultural meaning beyond what the recorded heritage and placename evidence directly attests.
Data caveats and limits
  • NMS Sites and Monuments Record is the product of survey campaigns conducted at different intensities across different counties and decades. Some baronies have been surveyed more thoroughly than others, and absolute counts should be read in that light. Sites destroyed by development before survey are typically not represented; sites in heavily forested or upland terrain are sometimes under-recorded.
  • NIAH coverage is broadly complete for the Republic of Ireland but the survey was conducted on a rolling county-by-county basis, and the most recent appraisal date varies. Buildings demolished or substantially altered after their original survey may still appear in the register; conversely, recent buildings of merit may not yet have been appraised.
  • Logainm classification applies a deliberately conservative pattern-matching approach to the Irish-language townland forms. The classifier prioritises true positives over recall: a townland may carry a heritage signal that the classifier doesn’t recognise, particularly where the diagnostic root has been heavily anglicised or where the townland name draws on a less common term. The 60,000+ townland records and ~9,800 classified placenames give a substantial signal at barony scale, but individual townland names should be checked against Logainm directly for definitive interpretation.
  • Period attribution. The chronological distribution reflects only those NMS sites that carry a recognised period attribution in the source data. Sites listed as “Unknown” period are excluded from the dated subset.
  • Boundary changes. Some baronies have undergone minor boundary adjustments since their 19th-century definition; the OSi 2019 generalised boundaries used here are the current statutory definition and may differ slightly from historical maps in border areas.
  • Bedrock geology is mapped at 1:100,000 scale, which means local variation within a barony — small pockets of different rock type, mineral veins, alluvium overlying bedrock — is generalised. The dominant-system and rocktype figures are area-weighted, so a barony reading “70% Carboniferous limestone” may still contain small but archaeologically important pockets of older or younger rock. Around 3% of GSI polygons do not match the lexicon and contribute no rocktype or system attribution.
Data sources
  • National Monuments Service — Sites and Monuments Record (SMR)
    Contributes archaeological site records, classifications, periods, and recorded protection-zone status.
    © Department of Housing, Local Government and Heritage · Licence: Open data, Creative Commons Attribution 4.0 (CC BY 4.0)
    https://data.gov.ie/dataset/national-monuments-service-archaeological-survey-of-ireland
  • National Inventory of Architectural Heritage (NIAH)
    Contributes listed-building records and architectural-significance grades.
    © Department of Housing, Local Government and Heritage · Licence: Open data, Creative Commons Attribution 4.0 (CC BY 4.0)
    https://data.gov.ie/dataset/national-inventory-of-architectural-heritage-niah-national-dataset
  • Logainm — Placenames Database of Ireland
    Contributes Irish-language and English townland names, civil parish associations, and barony assignments for the heritage-placename classifier.
    © Government of Ireland, Placenames Branch · Licence: Creative Commons Attribution-NoDerivs 3.0 Ireland (CC BY-ND 3.0 IE)
    https://www.logainm.ie/
  • Ordnance Survey Ireland — National Statutory Barony Boundaries 2019
    Contributes the canonical 280 barony boundaries (generalised 20m).
    © Ordnance Survey Ireland / Government of Ireland · Licence: Open data, Creative Commons Attribution 4.0 (CC BY 4.0)
    https://data-osi.opendata.arcgis.com/
  • EURODEM — European Digital Elevation Model
    Contributes elevation, slope, and topographic-wetness statistics, plus the hillshade rendering on each barony’s topographic map.
    © Maps for Europe · Licence: Open data
    https://www.mapsforeurope.org/datasets/euro-dem
  • ESA WorldCover
    Contributes land-cover classifications for grassland, woodland, cropland, wetland, urban, and water statistics.
    © European Space Agency · Licence: Creative Commons Attribution 4.0 (CC BY 4.0)
    https://esa-worldcover.org/en
  • Geological Survey Ireland — 1:100,000 Bedrock Geology
    Contributes bedrock geological data: dominant geological system (Carboniferous, Devonian, etc.), rock-type composition, and formation-level mapping, with the GSI Bedrock Lexicon providing descriptive attributes.
    © Geological Survey Ireland · Licence: Open data, Creative Commons Attribution 4.0 (CC BY 4.0)
    https://www.gsi.ie/en-ie/data-and-maps/Pages/Bedrock.aspx

Explore more: Search any of the 280 ROI baronies, browse by historical province, or read the methodology and data sources for the full Republic of Ireland Heritage Tool.

Spotted an error? This dataset is updated continuously. Email contact@danielkirkpatrick.co.uk with corrections, missing records, or suggestions for improvement.