Castlehill

106 registered freehold parcels lie mostly in Castlehill, from 93 m² to 312,816 m² (31.28 ha, 77.3 acres). The dashed line is the townland's boundary; 42 neighbouring parcels touch it.

Download the townland: DXF, in Irish Transverse Mercator metres, with its boundary, parcels and buildings; GeoJSON or KML.

No zone of a development plan covers Castlehill in the national zoning. Outside zoned towns and villages, the county development plan's rural policies apply to each application.

Source: Tailte Éireann and the Department of Housing (MyPlan), national zoning, CC BY 4.0.

• 17 Feb 2026Conditional

  Retention of existing dwelling house previous planning granted under P91/198. Including retention of garage, existing access, boundaries, all other associated works & services.

  Retention · Mayo County Council, 2660129

• 22 Dec 2025N/a

  Retention of existing dwelling house previous planning granted under P91/198. Including retention of garage, existing access, boundaries, all other associated works & services.

  Retention · Mayo County Council, 2660020

• 11 Mar 2022Conditional

  RETAIN AND COMPLETE HOUSE UNDER CONSTRUCTION, INSTALLATION OF SEPTIC TANK AND PERCOLATION AREA, AND ANCILLARY SITE WORKS. PREVIOUS GRANT OF PERMISSION REF. P10/164 & P10/1640 REFER, REVISIONS TO FRONT AND REAR ELEVATIONS AND CHANGE OF HOUSE TYPE TO SINGLE STOREY DWELLING HOUSE

  Permission · Mayo County Council, 22203

Source: National Planning Applications, Department of Housing, Local Government and Heritage, CC BY 4.0. Applicants are not shown.

Designated sites

• Special Area of Conservation: River Moy SAC 002298
• Special Protection Area: Lough Conn and Lough Cullin SPA 004228
• Proposed Natural Heritage Area: Lough Conn And Lough Cullin 000519

Recorded monuments

• MA038-114 Barrow - ring-barrow
  Description

  In pasture, located on a rise, with a fall of ground into a natural hollow at S and W. There are good views over surrounding undulating landscape, with Nephin dominating the skyline to SW. Circular platform (7.4m E–W; 7.5m N–S) defined by a fosse (Wth 1.6m) with an external stony bank (Wth 1.8-2.2m; int. H 0.3m; ext. H 0.4-0.6m). Overall diameter: 13.7m N–S; 13.4m E–W. The central platform is defined NE–SE by a slight scarp; it is less distinct on the W half where the fosse is largely infilled. The external stone bank is evident as a moss- and sod-covered rise of jumbled stones, with a break (Wth 2.4m) at WNW and another (Wth 1.5m) at NE. There is a hollow or pit (diam. 3-3.5m; D 0.45m) on the central platform, slightly off-centre to S. Remnants of relict field fence abut external bank at WNW. There is a rath (MA038-117----) 200m to SE. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-115 Enclosure
  Description

  In pasture, in undulating terrain overlooking a small river, the Fiddaunglass, c. 300m to NE. This monument is not shown on the 1838 OS 6-inch map; it is shown on the 1922 edition as a small hachured circle (diam. c. 10m). A slight rise in ground level marks the location; no other visible trace is evident. Its original form and function is unknown; it may have been a barrow, mound or hut site. A roughly N–S field fence lies immediately to E, or possibly overlies the original E edge of the monument. There is a rath (MA038-116----) located 20m to S. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-116 Ringfort - rath
  Description

  In pasture, located at the N end of a low N–S ridge. The rath straddles the narrow top of the ridge, utilising the steeply sloping W slope. Raised circular area (26.4m N–S; 26.9m E–W) defined by a scarp, and enclosed E–NNW by a fosse with traces of an external bank. The enclosing scarp (ext. H 2.3m at NNE; 1.8m at SW, 3.4m at W; Wth slope c. 4.5-6.5m) is enhanced by the natural fall of ground. It retains a slightly raised internal rim, with remnants of a stone kerb evident in parts at SSE–SSW. Stones protrude randomly from the external face of the scarp. A short semi-circular section of the enclosing scarp has been quarried out at the N. The fosse (Wth 3.4m; D 0.4-0.8m) is evident as a shallow depression ESE–S, best defined at SSE-S where it cuts across the spine of the ridge; at SW–NW, where it coincides with the steep ridge slope, it changes to a terrace (Wth 2-2.5m) with an external stony scarp (H 1m) cut into the natural slope; the terrace terminates at N. The fosse is not evident at N–NE, and is overlain by a later roughly N–S field fence at E. There is a possible external bank, evident as a low, sod-covered stony rim (Wth 2-2.4m), on the outer edge of the fosse at ESE–SW. The interior is highest at SW, sloping down gently from there to NE. At the E a poorly defined, slumped gap (Wth c. 2m) appears to mark the original entrance; a slight rise in ground level outside the gap may mark the remnants of access ramp or causeway. Immediately inside the entrance, on the S side, a shallow, oblong depression (8.4m NE–SW; 4.5m NW–SE; D 0.4m) extends to the SE into the interior. The rath is ringed with hazel scrub. There is an enclosure (MA038-115----) located 20m to N. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-117 Ringfort - rath
  Description

  In undulating average pasture, located on a rise, with good views to E and SE over an expanse of lowlying, wettish land. This possible rath is shown on the 1838 OS 6-inch map as a circular ringfort-like enclosure (diam. 25-30m), boxed in by field walls; it is depicted on later map editions as a mix of oblong and linear hachured features. It has been greatly damaged, and it is difficult to trace its original form. A field wall, on an E–W axis, now bisects the location. To N of the wall, a barely discernible undulation outlines a semi-circular area (25m E–W; c. 12m N–S), possibly the N third of the enclosure. To S of the wall, a stone bank can be traced in a broad arc ESE–SW, which preserves the S arc of the enclosure. The stone bank is evident now as a sod-covered rise (Wth 2m at top, 2.3-3.7m overall), very low internally, with an almost vertical external scarp (H 0.5-0.7m) faced with large stones and boulders; this stone facing is probably the result of later modification/incorporation into a field wall. The stone bank enclosing a broadly semi-circular space (c. 27m E–W; 20.6m N–S to field wall at N), part of the original rath interior. The S portion of this space is traversed by E–W cultivation ridges, but to N of this, it has been largely quarried out (D 0.7m). Outside the stone bank the ground falls to S in a broad natural slope defined at its base by remnants of walling. There is another possible rath (MA038-118----) 140m to S. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-118 Enclosure
  Description

  In pasture, located on a low elevation, with a fall of ground to E to an area of flat wettish ground. This possible rath is shown on the 1838 OS 6-inch map as a circular enclosure (diam. c. 40m), bisected to N of centre by a NE–SW field boundary; by the time of the 1922 edition, only the NW third is shown, depicted as a semi-circular hachured area with the straight side to SE. It has been levelled. An oblong rise (16m NW-SE; c. 25-30m NE–SW), defined along its NW arc by a slight scarp, representing the NW-N arc of the enclosure, can still be discerned. Further faint undulations are visible to S, but the full outline of the enclosure is no longer visible at ground level. There is another possible rath (MA038-117----) 140m to N. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-119 Ringfort - rath
  Description

  In average pasture, located on a NW–SE ridge. Circular area (35.4m NE–SW; 37m NW–SE) enclosed at NNE–SW by a low earth and stone bank (Wth 2.6m; int. H 0.4m; ext. H 0.4m at S), levelled at SW–N to a low undulation. A modern field wall stands 2m outside the bank at NNE–SW, mirroring the curve of the rath; this wall is shown fully encircling the rath on the 1922 OS 6-inch map, but has since been removed on the W half. In the SE quadrant of the interior, there is a slightly raised, stony L-shaped area (c. 6m N–S; 6m E–W) defined on the E and S sides by a slight scarp. It function is unclear. A post and wire property fence, on NE–SW axis, centrally bisects the rath interior. A WNW–ESE farm road lies immediately to N of the rath. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-120 Ringfort - rath
  Description

  In average pasture, located on top of a gravel ridge, with a fall of ground to N and SE, providing fine views over flat, lowlying pasture to N and gently undulating terrain to S–SW. This rath is named ‘Rathcoultia’ on the 1838 and 1922 OS 6-inch maps, where it is depicted as circular; the E half has since been levelled. A property fence on a NNW–SSE axis bisects the rath roughly centrally. The W half of the rath survives as a slightly raised semi-circular area (30m N–S; 17m E–W to fence), defined S–NNW by a sod-covered earthen bank (Wth 2.6m; int. H 0.2-0.4m; ext. H 0.7m at NW). At SW, 2m outside the bank there are remnants of a second bank. This is engulfed in overgrowth, and it is unclear if it is an original external bank or merely the remnants of a later field fence. The interior of the W half is traversed by relict N–S cultivation ridges. To E of the property fence, the rath has been levelled, except for a short arc of enclosing scarp at SE–S, which is preserved in the line of a NE–SW field fence. Hawthorn, blackthorn and brambles grow on the perimeter at S and W. Compiled by: Jane O'Shaughnessy Date of upload: 13 August 2019

• MA038-121 Ringfort - rath
  Description

  In improved pasture, located on a low NW–SE gravel ridge with extensive views to N–SE. This possible rath is named ‘Lisduff’ on the 1838 and 1922 OS 6-inch maps, where it is shown as a circular enclosure with trees planted in the interior. The E two thirds of the enclosure have been levelled, but the outline of the original circular area (c. 27m NE–SW; c. 28m NW–SE) can still be discerned. The enclosing bank on the W arc is upstanding. It consists of a broadly slumped scarp (Wth 3.3m-c. 5m; ext. H 1.6m), topped with stones, and is largely obscured by dense overgrowth. Immediately outside this, and mirroring its curve, are tumbled remnants of stone-built field wall. At NNE–SSW the enclosing bank has been levelled, but its curving outline can still be traced as a slightly raised undulation, most clearly visible at NE and S–SSW, where it coincides with the ridge contours. A field fence, on a NE–SW axis, extends across the NW edge of the enclosure. There is a possible rath (MA038-122----)150m to NW, and an enclosure (MA038-123----)135m to SSW. Compiled by: Jane O'Shaughnessy Date of upload: 14 August 2019

• MA038-122 Enclosure
  Description

  In improved pasture, located on a rise with a pronounced N-facing slope. Shown on the 1838 and 1922 OS 6-inch maps as a circular ringfort-like enclosure (diam. c. 25m). It has been entirely levelled; there is no visible trace at ground level. A rath (MA038-121----) is located c. 155m to SW, and another (MA038-120----) is c. 190m to NW. Compiled by: Jane O'Shaughnessy Date of upload: 14 August 2019

• MA038-123 Enclosure
  Description

  In pasture, on the former demesne lands of Castlehill House, located on the SW side of a narrow WNW–ESE gravel ridge. Views are restricted by rising ground to N–NE, but there is a broad vista of rolling grasslands to S. Shown as a circular enclosure on the 1838 OS 6-inch map; by the time of the 1922 edition it is shown enclosed by a wall and the interior is planted with trees. Slightly raised circular flat-topped area (24m N–S; 24.6m E–W) defined by a low, poorly defined scarp (H 0.4m). A few stones protrude in parts along the rim of the scarp. A modern mortared stone wall encircles the enclosure, at a distance of 3.8m from the scarp. The scarp is ringed with oak trees. A few Scot’s pine grow in the interior, which is dotted with tree stumps. The original function of this enclosure is not clear –it may have been constructed as a tree-ring or it may be an earlier enclosure or rath modified to serve as a tree-ring. Compiled by: Jane O'Shaughnessy Date of upload: 14 August 2019

• MA038-124 Castle - unclassified
  Description

  This castle is not indicted on the 1838 and 1922 OS 6-inch maps. There are no upstanding remains, and some uncertainty about its exact location. Castlehill House, a 19th century country house, located within a few hundred meters of the W shores of Lough Conn, is said to be built on or close to the site of the castle. The 1838 OS Letters record that the foundations of the castle were uncovered in the 1830’s during the construction of Castlehill House: ‘At the site of this castle, which lies close by Mr. Walshe’s new house in Keerhanann, alias Castlehill Townland in Addergoole Parish, there is to be seen a good deal of the rubbish of its foundations, dug up since the commencement of this new building.’ (O’Flanagan 1927, 183-4 (72-3)). Further details were recorded in another letter: ‘Tradition says there were two castles here, occupied one by William, and the other by Richard Barrett. Both fell in after times into the possession of the family of the Cormacks, who became extinct. We learn in the Annals of the Four Masters at the year A.D. 1526 that this castle and the castle of Crossmolina [MA029-039----] were demolished by O’Donnell –the words are:-“O’Donnell marched an army into Connaught at the request of the descendants of Richard Burke….He took the Castles of Caorthanan and Crossmaoiliona, in which he obtained many hostages and spoils, he threw down and totally demolished these castes in order that they might be no longer habitable. He afterwards established peace between the descendants of Richard Burke and the Barretts.” (Ibid. 352 (180). Aldridge (1986-87, 65) surmised that the exposed castle foundations mentioned in the OS Letters must have been immediately to W of Castlehill house, and notes that ‘one or two of the carved stones from it are incorporated into the garden buildings which stand there now.’ Compiled by: Jane O'Shaughnessy Date of upload: 14 August 2019

• MA038-163 Enclosure
  Description

  The Archaeological Survey of Ireland (ASI) is in the process of providing information on all monuments on The Historic Environment Viewer (HEV). Currently the information for this record has not been uploaded. To access available information for research purposes please make an appointment in advance with the Archive Unit (open Fridays 10.00 am – 5.00 pm), Department of Housing, Local Government and Heritage, The Custom House, Dublin 1 D01W6XO or email NMarchive@housing.gov.ie.

Architectural heritage

• Castlehill House, farm house, 1835–1845 · Regional interest
  Description

  Detached three-bay (single-bay deep) two-storey over basement[?] farmhouse, under construction 1838, on a T-shaped plan centred on single-bay full-height breakfront with single-bay (single- or two-bay deep) full-height central return (west). Vacant, 1901. Occupied, 1911. Vacant, 1942. Hipped slate roof on a T-shaped plan centred on hipped slate roof (west) with paired limestone ashlar central chimney stacks having cut-limestone capping, and cast-iron rainwater goods on cut-limestone stepped cornice retaining embossed cast-iron hoppers and downpipes. Part creeper-covered fine roughcast walls on drag edged tooled cut-limestone chamfered cushion course on roughcast plinth. Segmental-headed central door opening in (full-height) camber-headed recess approached by flight of four drag edged tooled cut-limestone steps, cut-limestone doorcase with engaged Doric columns on plinths supporting "Cyma Recta" or "Cyma Reversa" cornice, and cut-limestone surround on padstones framing glazed timber panelled door having fanlight. Square-headed window openings in (full-height) camber-headed recesses with cut-limestone sills, and concealed dressings framing six-over-six timber sash windows. Interior including (ground floor): central entrance hall retaining carved timber surrounds to door openings framing timber panelled doors, and plasterwork cornice to ceiling; and carved timber surrounds to door openings to remainder framing timber panelled doors with timber panelled shutters to window openings on panelled risers. Set in landscaped grounds with drag edged rock faced limestone ashlar piers to perimeter having drag edged rock faced cut-limestone shallow pyramidal capping supporting cast-iron double gates.

Designated sites: National Parks and Wildlife Service. Recorded monuments: Sites and Monuments Record, National Monuments Service. Buildings: National Inventory of Architectural Heritage. Department of Housing, Local Government and Heritage, CC BY 4.0. Works at or in relation to a recorded monument need two months' written notice to the National Monuments Service (National Monuments (Amendment) Act 1994, section 12).

Radon

About 1 in 5 homes in this area is likely to have high radon levels. Testing a home

Landslides

Susceptibility moderately low, low, low (inferred), on the 1:50,000 map.

Terrain model

No LiDAR survey of the Office of Public Works covers the centre of the townland of Castlehill.

Flooding

The flood maps of the Office of Public Works: floodinfo.ie.

Radon Risk Map of Ireland, Environmental Protection Agency; Landslide Susceptibility Classification, Geological Survey Ireland; both CC BY 4.0. LiDAR: contains Irish Public Sector Data (Geological Survey Ireland & the Office of Public Works) licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence.

No address of the register names Castlehill with five sales or more. The sales of the area are on the page of Co. Mayo.

Name

Castlehill · Caorthannán

Area

3,029,727 m² (302.97 ha, 748.66 acres)

Civil parish

Addergoole, and its townlands

Barony

Tirawley

Electoral division

Crossmolina South, the unit of the census

Census 2022

Crossmolina South electoral division: 870 people in 349 households; 82% of households own their home; 34% of homes were built since 2001; 16% of dwellings stood vacant on census night, and 9% were holiday homes.

Neighbouring townlands

Ballyduffy, Cabragh, Caffoley, Cum, Dervin, Killeen, Lecarrow, Sranalaghta South

Placenames

Castlehill on logainm.ie, the Placenames Database of Ireland

Townlands, civil parishes, baronies and electoral divisions, National Statutory Boundaries, Tailte Éireann, CC BY 4.0. Census 2022, Small Area Population Statistics by electoral division, Central Statistics Office, CC BY 4.0. A townland is the smallest land division of Ireland, and the unit of a rural address; old registers such as the 1901 and 1911 censuses file it under its civil parish and barony.