Gwynedd Archaeological Trust
Regional Historic Environment Record

Dinas Gynfor Promontory Fort, Llanlleiana

Primary Reference Number (PRN) : 3067
Trust : Gwynedd
Community : Llanbadrig
Unitary authority : Ynys Mon
NGR : SH39069507
Site Type (preferred type first) : PREHISTORIC PROMONTORY FORT
Status : Scheduled Monument

Description :
An Iron Age promontory fort with precipitous cliffs to the sea on three sides and steep slopes with walling, to a marshy valley on the landward side. (RCAHMW, 1937)

An Iron Age promontory fort defended by precipitous cliffs except in the SW where the defence is a single bank averaging 1.2m high across a steep natural slope with a marsh at the bottom. Quarrying in the N has destroyed a possible bank. Condition fair but somewhat mutilated by quarrying. <2>

SH 39069507 Dinas Gynfor - noted by OS. <3>

Article describing condition of monument and 'history', published 1876. <4>

Description of site. <6>

Not visited. (Smith, 2005)

Sources :
Cooke, N. , 2014 , Rhyd-y-Groes Repower, Anglesey: Cultural Heritage Assessment. ( © Wessex Archaeology)
Hadley, A. , 2016 , Proposed Wind Turbine at Nant-y-fran, Cemaes, Isles of Anglesey. Cultural Heritage Impact Assessment. ( © Archaeology Wales)
Smith, G. , 2003 , Prehistoric Defended Enclosures: Scoping for Pan-Wales Assessment ( © GAT)
Smith, G. , 2005 , A Survey of Prehistoric Defended Enclosures in North West Wales 2004-2005: West Conwy, Gwynedd (Arfon) & Anglesey ( © GAT)
Smith, G. , 2008 , Iron Age Settlements in Wales: Cadw Defended Enclosures Publication Hillforts and Hut Groups in North-West Wales ( © GAT)
The Royal Commission on the Ancient and Historical Monuments of Wales , 1937 , An Inventory of the Ancient Monuments in Anglesey
Waddington, K. , 2010 , Early Celtic Societies in North Wales
Waddington, K. , 2013 , The Settlements of Northwest Wales: From the Late Bronze Age to the Early Medieval Period
Wynne Williams, W. , 1876 , Mona Antqua: Dinas and Morwydd Ymrawyr
Ordnance Survey , 1969 , SH39NE 1 , <2>
Ordnance Survey , 1963 , SH39NE 1 , <3>
Williams, W. W. , 1876 , Archaeologia Cambrensis , <4>
Latham, J. , 1985 , Anglesey , <6>
Lynch, F. , 2009 , Anglesey Past Landscapes of the Coast , <8>

Events :
40621 : Prehistoric Defended Enclosures in North-west Wales, 2004-5: West Conwy, Gwynedd (Arfon) and Anglesey (year : 2005)
44557 : Early Celtic Societies in North Wales (year : 2010)
45013 : Rhyd-y-Groes Repower, Anglesey: Cultural Heritage Assessment. (year : 2014)
45042 : Iron Age Settlements in Wales: Cadw Defended Enclosures Publication. Hillforts and Hut Groups in North-West Wales. (year : 2008)
40620 : Prehistoric Defended Enclosures: Scoping for Pan-Wales Assessment (year : 2003)
45130 : Proposed Wind Turbine at Nant-y-fran, Cemaes, Isle of Anglesey. Cultural Heritage Impact Assessment. (year : 2016)

Related records
National Monuments Record Wales NPRN 95547 https://coflein.gov.uk/en/site/95547/

Compiled date : 31-03-2000


Images :



The above data are supplied by GAT in partnership with its Local Authorities (Anglesey, Conwy and Gwynedd County Councils, and Snowdonia National Park Authority), © GAT 2025 (and in part © Crown, 2025 - as indicated)
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