LiDAR 1m DTM Hillshade
Satellite Imagery
LiDAR 1m DTM Hillshade
Satellite Imagery
Scroll left/right to view further images.
HER: Gwynedd 5 (None)
NMR: SH 11 SE (95283)
SM: CN017
NGR: SH54976530
X: 254970 Y: 365300 (OSGB36)
Substantial contour hillfort located on prominent long NE-SW ridge between two marshy stream valleys of the headwaters of the Afon Cegin to SE and NW and stream running into the Afon Seiont on SW. Surrounding slopes moderate to strong with internal area of 1ha. Two phases of construction from simple stone-walled univallate enclosure to massive multivallate fort with three earth and rubble glacis banks (rare for north Wales), up to 12m thick and 9m high, with deep ditches, that on outer some 4m wide for most of circuit with counterscarp (Gardner 1947; Evans and Smith 2007). On N wedge-shaped annexe in the space between the outer rampart and the steep slope of the hill; now part of farm yard and fort generally affected by farm here and woodland on NW side. Simple entrance through the stone-built 3.3m rampart and another smaller on W side kept when ramparts remodelled through the three earth and rubble banks. The larger of the two entrances through the wall is obstructed by inner rampart, suggesting that ramparts later than the wall and confirming phased construction. Single hut visible as a depression on W. Possible bronze spearhead found. Interior pasture, banks with scrub and gorse. Wooded on NW. Much affected by working farm to NE, but substantial site. On 1st Ed. OS map (1889). Undated.
Citizen Science: ✗
Reliability of Data: Confirmed
Reliability of Interpretation: Confirmed
X: -464306 Y: 7013576 (EPSG: 3857)
Longitude: -4.170935427312046 Latitude: 53.16499598874719 (EPSG:4326)
Country: Wales
Current County or Unitary Authority: Gwynedd
Historic County: Caernarfonshire
Current Parish/Community/Council/Townland: Llanddeiniolen
Much affected by working farm on NE and annexe on N now part of farm yard. Modern slate boundary runs across the site from SW to NE.
| Extant | ✓ |
| Cropmark | ✗ |
| Likely Destroyed | ✓ |
Interior pasture, banks with scrub and gorse. Wooded on NW.
| Woodland | ✓ |
| Commercial Forestry Plantation | ✗ |
| Parkland | ✗ |
| Pasture (Grazing) | ✓ |
| Arable | ✗ |
| Scrub/Bracken | ✗ |
| Bare Outcrop | ✗ |
| Heather/Moorland | ✗ |
| Heath | ✗ |
| Built-up | ✗ |
| Coastal Grassland | ✗ |
| Other | ✗ |
Substantial contour hillfort located on prominent long NE-SW ridge between two marshy stream valleys of the headwaters of the Afon Cegin to SE and NW and stream running into the Afon Seiont on SW. Surrounding slopes moderate to strong.
| Contour Fort | ✓ |
| Partial Contour Fort | ✗ |
| Promontory Fort | ✗ |
| Hillslope Fort | ✗ |
| Level Terrain Fort | ✗ |
| Marsh Fort | ✗ |
| Multiple Enclosure Fort | ✗ |
| Hilltop | ✗ |
| Coastal Promontory | ✗ |
| Inland Promontory | ✗ |
| Valley Bottom | ✗ |
| Knoll/Hillock/Outcrop | ✗ |
| Ridge | ✓ |
| Cliff/Plateau-edge/Scarp | ✗ |
| Hillslope | ✗ |
| Lowland | ✗ |
| Spur | ✗ |
Dominant Topographic Feature: Long ridge
| North | ✗ |
| Northeast | ✗ |
| East | ✗ |
| Southeast | ✗ |
| South | ✗ |
| Southwest | ✗ |
| West | ✗ |
| Northwest | ✗ |
| Level | ✓ |
Altitude: 169.0m
N/A
None
Reliability: D - None
| Pre 1200BC | ✗ |
| 1200BC - 800BC | ✗ |
| 800BC - 400BC | ✗ |
| 400BC - AD50 | ✗ |
| AD50 - AD400 | ✗ |
| AD400 - AD 800 | ✗ |
| Post AD800 | ✗ |
| Unknown | ✓ |
| Pre Hillfort: | None |
| Post Hillfort: | None |
On 1st Ed. OS map (1889). RCAHMW investigations 1948-54. GAT investigations 1985, 1988. 1991, 1996. GAT prehistoric defended enclosures survey 2004-2005. GAT archaeological evaluation 2007.
| 1st Identified Map Depiction (1889): | OS map. |
| Other (1967): | Visit by the Hillfort Study Group |
| Other (2007): | GAT archaeological evaluation. |
| Other (None): | RCAHMW investigations. |
| Other (None): | GAT investigations. |
| Other (None): | GAT prehistoric defended enclosures survey. |
Single hut visible as a depression on W. Possible bronze spearhead found.
Stream 0.2km outside fort.
| None | ✓ |
| Spring | ✗ |
| Stream | ✗ |
| Pool | ✗ |
| Flush | ✗ |
| Well | ✗ |
| Other | ✗ |
Single hut visible as a depression on W.
| No Known Features | ✗ |
| Round Stone Structures | ✗ |
| Rectangular Stone Structures | ✗ |
| Curvilinear Platforms | ✗ |
| Other Roundhouse Evidence | ✓ |
| Pits | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
None
| No Known Excavation | ✓ |
| Pits | ✗ |
| Postholes | ✗ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Roads/Tracks | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
| Nothing Found | ✗ |
None
| No Known Geophysics | ✓ |
| Pits | ✗ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Roads/Tracks | ✗ |
| Quarry Hollows | ✗ |
| Other | ✗ |
| Nothing Found | ✗ |
Possible bronze spearhead found.
| No Known Finds | ✗ |
| Pottery | ✗ |
| Metal | ✓ |
| Metalworking | ✗ |
| Human Bones | ✗ |
| Animal Bones | ✗ |
| Lithics | ✗ |
| Environmental | ✗ |
| Other | ✗ |
None
| APs Not Checked | ✓ |
| None | ✗ |
| Roundhouses | ✗ |
| Rectangular Structures | ✗ |
| Pits | ✗ |
| Postholes | ✗ |
| Roads/Tracks | ✗ |
| Other | ✗ |
Simple entrance through the stone-built 3.3m rampart on E and another smaller on W side kept when ramparts remodelled through the three earth and rubble banks. The larger of the two entrances through the wall is obstructed by inner rampart, suggesting that ramparts later than the wall and confirming phased construction. Second gap on W probably modern.
| 3: | Second gap on W probably modern. |
| 2: | None |
Guard Chambers: ✗
Chevaux de Frise: ✗
| 1. Simple Gap (West): | None |
| 2. Simple Gap (East): | None |
Two phases of construction from simple stone-walled univallate enclosure to massive multivallate fort with three earth and rubble glacis banks (rare for north Wales), up to 12m thick and 9m high, with deep ditches, that on outer some 4m wide for most of circuit with counterscarp.
| Area 1: | 1.0ha. |
| Total: | 1.0ha. |
Total Footprint Area: Noneha.
None
| ✓ | Two phases of construction. |
| ✗ | None |
| NE Quadrant: | 3 |
| SE Quadrant: | 3 |
| SW Quadrant: | 3 |
| NW Quadrant: | 3 |
| Total: | 3 |
| Partial Univallate | ✗ |
| Univallate | ✗ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✓ |
| Unknown | ✗ |
| Partial Univallate | ✗ |
| Univallate | ✓ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✗ |
Earth and rubble glacis banks. Good counterscarp.
| None | ✗ |
| Earthen Bank | ✓ |
| Stone Wall | ✗ |
| Rubble | ✓ |
| Wall-walk | ✗ |
| Evidence of Timber | ✗ |
| Vitrification | ✗ |
| Other Burning | ✗ |
| Palisade | ✗ |
| Counter Scarp Bank | ✓ |
| Berm | ✗ |
| Unfinished | ✗ |
| Other | ✗ |
None
| None | ✗ |
| Earthen Bank | ✗ |
| Stone Wall | ✗ |
| Murus Duplex | ✗ |
| Timber-framed | ✗ |
| Timber-laced | ✗ |
| Vitrification | ✗ |
| Other Burning | ✗ |
| Palisade | ✗ |
| Counter Scarp Bank | ✗ |
| Berm | ✗ |
| Unfinished | ✗ |
| No Known Excavation | ✓ |
| Other | ✗ |
| ✗ | None |
| ✓ | Deep ditches. |
Number of Ditches: 3
| ✓ | On N wedge-shaped annexe in the space between the outer rampart and the steep slope of the hill; now part of farm yard and paddock. |
Evans, R. and Smith, G. 2007. Dinas Dinorwig, Llanddeiniolen Archaeological Evaluation, G1968 Report No. 708, Bangor: Gwynedd Archaeological Trust.
Gardner, W. 1947. Dinorwig Hill-fort, Llanddeiniolen, Caernarvonshire, Arch Camb, XCIX, 2, 231-48.
Lynch, F. 1995. A guide to ancient and historic Wales - Gwynedd, London: HMSO, 73-4.
RCAHMW 1960. Caernarvonshire Vol II: Central, A survey and inventory by the Royal Commission on Ancient and Historical Monuments in Wales and Monmouthshire, No 1170, London: HMSO
Smith, G. H. 2005 , A Survey of Prehistoric Defended Enclosures in North West Wales 2004-2005: West Conwy, Gwynedd (Arfon) and Anglesey, Bangor: Gwynedd Archaeological Trust.
Waddington, K. 2013. The Settlements of Northwest Wales: From the Late Bronze Age to the Early Medieval Period, Cardiff: University of Wales Press.
Atlas of Hillforts:
Wikidata:
This work is licensed under CC BY-SA 4.0
and should be cited as:
Lock, Gary and Ralston, Ian. 2024. Atlas of Hillforts of Britain and Ireland. Available at: https://hillforts.arch.ox.ac.uk
Document Version 1.1