Gwynedd Archaeological Trust
Regional Historic Environment Record

Twyn y Parc Promontory Fort, Malltraeth

Primary Reference Number (PRN) : 3024
Trust : Gwynedd
Community : Bodorgan
Unitary authority : Ynys Mon
NGR : SH36816492
Site Type (preferred type first) : PREHISTORIC PROMONTORY FORT
Status : Site of Special Scientific Interest

Description :
Situated on a rocky coastal headland. The promontory rises to a maximum height of 100ft and in most places has precipitous cliffs to the sea. Defences concentrated on the neck where a massive major rampart and two subsidiary banks isolate it from the mainland. The remains of a wall on an artificial terrace 150yds long was an additional defence. (RCAHMW, 1937)

1938 Sir George Meyrick found a part of a mortarium dated C3rd of C4th, a pot boiler was also found and in 1939 an iron spearhead, 10 1/2" long and 3ins in breadth. Also a fragment of a crucible with traces of copper. <2>

Trwyn-y-parc is as described. The height of the ramparts varies from 0.3m to 2.4m. <3>

SH 36816492 Twyn-y-parc noted by OS. <4>

As described with stone revetting walls along the N and NW sides. (Davidson & Jones, 1997)

A promontory with sheer cliffs on three sides. The approach to it from the mainland is defended by large bivallate dump ramparts and ditches. At the north-east, where the cliffs are less sheer and there is a small inlet, an orthostat-faced wall was added along the edge of the cliff slope. There are no identifiable internal buildings but only one area could have been occupied, a natural terrace close behind the eastern ramparts. Here any hut platforms could have been masked by blown sand and random exploratory excavation by the landowner has produced an iron spearhead and pottery of the 3rd-4th century AD. (Smith, 2005)

The outer rampart is relatively small and low providing simply an obstruction to attack. The inner rampart however is much larger and extremely well preserved at c.2.5m high and still very steep suggesting that beneath the grass it might also suggest that it was refurbished during sub-Roman occupation. It is surprising that there is no trace of internal settlement features. Possibly the area was subject to sand blow in the 14thC (when Newborough was affected). Certainly the area to the east, inland is covered in sand, so there could be well-preserved features. Possibly geophysics could be tried. The finds made by Sir George Meyrick in 1938-39 should be located and published. (Smith, 2005)

Twyn y Parc is an impressive promontory fort which is defined on its northeast side by a massive 70m-long stone-faced rampart, which bounded the cliff promontory on the landward side (Figure 6.10). Two additional outer stone-faced banks further isolated the site from the mainland, although these were much slighted. The main entrance was approached along a causewayed track which winds between the outer ramparts and through a simple gap within the inner rampart at the northern end (G. Smith 2005) this made direct approach impossible. There are no traces of internal occupation features the interior is extremely rocky and uneven and it is possible that the area is overlain by accumulations of wind-blown sand (G. Smith 2005). In the late 1930s, Meyrick conducted some very minor excavations, just inside the rampart. He recovered finds such as a sherd of mortarium dating to the third or fourth century AD, a group of coins dating from the late-third and early-fourth centuries AD, as well as an iron spearhead (Hughes 1939, 989; Lynch 1991, 233). A crucible fragment with copper-alloy residues indicates that the site was once a focus for bronze casting. No spatial or contextual information was provided for the finds, but the evidence suggests that the site was occupied in the first millennium BC and became a focus for re-occupation during the later Romano-British period. (Waddington, 2013)

Sources :
Davidson, A. & Jones, S. , 1997 , Coastal Erosion Survey: Anglesey ( © GAT)
Prtichard, H. , 1875 , Twyn y Parc
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
Williams, I. , 1945 , Transactions of the Anglesey Antiquarian Society , <2>
Ordnance Survey , 1970 , SH36SE 1 , <3>
Ordnance Survey , 1963 , SH36SE 1 , <4>
Lynch, F. , 2009 , Anglesey Past Landscapes of the Coast , <8>

Events :
40362 : Coastal Erosion Survey: Anglesey (year : 1997)
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)
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)

Related records
National Monuments Record Wales NPRN 93864 https://coflein.gov.uk/en/site/93864/

Compiled date : 06-04-1987


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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