LiDAR 1m DTM Hillshade
Satellite Imagery
LiDAR 1m DTM Hillshade
Satellite Imagery
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HER: Gwynedd 4361 (None)
NMR: SH 29 SE (54410)
SM: None
NGR: SH29189175
X: 229180 Y: 391750 (OSGB36)
Possible coastal promontory fort located on the W-facing promontory of Ynys-y-Fydlyn, NE Anglesey. First noted 1988. Ynys-y-Fydlyn is a distinctive promontory, a natural island joined to the mainland by a small spit of sand. Rocky to N, S, W with landward approach to E. Internal area not established. Here grassed-over bank, 0.75m high and 4m wide seems to protect the only landward approach. Has appearance of rampart, but ditch appears to be inside the bank. No entrance determined. Neck of the promontory is fractured leaving the seaward end inaccessible, while the landward end is now under forestry and is also largely inaccessible. Public access and subject to visitor pressure. Minimal investigations, undated.
Citizen Science: ✗
Reliability of Data: Unconfirmed
Reliability of Interpretation: Unconfirmed
X: -508792 Y: 7056374 (EPSG: 3857)
Longitude: -4.570553687178239 Latitude: 53.394863183801334 (EPSG:4326)
Country: Wales
Current County or Unitary Authority: Isle of Anglesey
Historic County: Anglesey
Current Parish/Community/Council/Townland: Cylch-y-Garn
Public access and bank subject to visitor pressure as crossed by footpath. National Trust owned.
| Extant | ✓ |
| Cropmark | ✗ |
| Likely Destroyed | ✗ |
Coastal grassland and bare rock.
| Woodland | ✗ |
| Commercial Forestry Plantation | ✗ |
| Parkland | ✗ |
| Pasture (Grazing) | ✗ |
| Arable | ✗ |
| Scrub/Bracken | ✗ |
| Bare Outcrop | ✗ |
| Heather/Moorland | ✗ |
| Heath | ✗ |
| Built-up | ✗ |
| Coastal Grassland | ✓ |
| Other | ✗ |
Possible coastal promontory fort located on the distinctive W-facing promontory of Ynys-y-Fydlyn in NE Anglesey. First noted 1988. Ynys-y-Fydlyn is a distinctive promontory, a natural island joined to the mainland by a small spit of sand. Rocky to N, S, W with landward approach to E.
| 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: Coastal headland.
| North | ✗ |
| Northeast | ✗ |
| East | ✗ |
| Southeast | ✗ |
| South | ✗ |
| Southwest | ✗ |
| West | ✗ |
| Northwest | ✗ |
| Level | ✓ |
Altitude: 20.0m
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 |
GAT investigation 1989. GAT Coastal Erosion Survey, 1997. GAT prehistoric defended enclosures survey 2004-2005.
| Other (1987): | GAT Coastal Erosion Survey. |
| Other (1989): | GAT investigation. |
| Other (None): | GAT prehistoric defended enclosures survey. |
None
None
| None | ✓ |
| Spring | ✗ |
| Stream | ✗ |
| Pool | ✗ |
| Flush | ✗ |
| Well | ✗ |
| Other | ✗ |
None
| 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 | ✗ |
None
| 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 | ✗ |
Entrance not determined.
| 0: | None |
| 2: | None |
Guard Chambers: ✗
Chevaux de Frise: ✗
Grassed-over bank, 0.75m high and 4m wide seems to protect the only landward approach. Has appearance of defensive work, but ditch appears to be inside the bank. Neck of the promontory is fractured leaving the seaward end inaccessible.
| Area 1: | Noneha. |
| Total: | Noneha. |
Total Footprint Area: Noneha.
None
| ✗ | Area not defined. |
| ✗ | position of ramparts estimated and not determined exactly. |
| NE Quadrant: | 1 |
| SE Quadrant: | 1 |
| SW Quadrant: | 0 |
| NW Quadrant: | 0 |
| Total: | 1 |
| Partial Univallate | ✓ |
| Univallate | ✗ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✗ |
| Unknown | ✗ |
| Partial Univallate | ✗ |
| Univallate | ✗ |
| Partial Bivallate | ✗ |
| Bivallate | ✗ |
| Partial Multivallate | ✗ |
| Multivallate | ✗ |
Nature of bank not determined.
| 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 |
| ✓ | Possible ditch, but reported inside bank. |
Number of Ditches: 1
| ✗ | None |
Jones, S. 1997. Coastal Erosion Survey, GAR Report 251, Bangor: Gwynedd Archaeological Trust.
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:
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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