Castell Cynfal, Bryn Crug

Has been described as a Certain Timber Castle (Motte)

There are earthwork remains

NameCastell Cynfal, Bryn Crug
Alternative NamesCynfael; Towyn; Bryn y Castell
Historic CountryMerioneth
Modern AuthorityGwynedd
1974 AuthorityGwynedd

Castell Cynfal is an isolated motte identified with a castle destroyed in 1147 and probably established only a short time before. The castle mound is situated above a line of crags on the crest of an isolated ridge on the lower slopes of the mountains on the south side of the Dysynni vale. This is a circular ditched mound, 42m in diameter & 5.0m high. The rock-cut ditch is some 3.0m accross & 1.0m deep. The summit of the mound is dished, producing an enclosed area about 12.5-13.5m across defined by a 1.0m high bank. There are no indications of further works. (Coflein–John Wiles 10.07.07)

The monument comprises the remains of a motte and ditch, dating to the medieval period (c. 1066 -1540 AD). A motte is a large conical or pyramidal mound of soil and/or stone, usually surrounded by either a wet or dry ditch, formerly surmounted by a tower constructed of timber or stone. Castell Cynfal is a modest but remarkably well preserved motte built on a prominent natural boss of rock commanding an impressive view to the SW and NW across the valley of the Afon Dysynni. Immediately to the NW there is a precipitous drop of over 30m but elsewhere the slope is not so steep nor is the fall so marked as the ground level rises towards Cynfal-fach. The interior on the top of the mound is roughly circular, measuring c.12m in diameter internally. There is a low bank around the edge of the mound but this is very spread and in places is more than 4m wide, while only 0.5m-0.75m high. From the crest of the bank the slope of the mound falls steeply c.5m-6m on all sides to the base of a well preserved rock-cut ditch. This is particularly impressive on the SW and NE where it is up to 4.5m wide and 1.3m deep below the external ground level, but it does in fact continue around the complete perimeter, even along the top of the precipice on the NW

There may, however, be an interruption on the ESE which could mark the position of an entrance leading in from a slight, possibly artificial, ramp up the natural rock slope. A bailey could perhaps have existed to the SW, but the area has been cultivated so that now no evidence remains, although it is possible that some of the irregularities close to the edge of the precipice on the NW may be of some antiquity. The motte was built in 1147 by Cadwaladr ap Gruffudd ap Cynan and was defended by Morfran, lay-abbot of the clas of Tywyn, but was captured later that year by Cadwaladr’s nephews, Hywel and Cynan, sons of Owain Gwynedd. (Scheduling Report)

Gatehouse Comments

Motte and bailey design, though by the Welsh, not the Norman invaders. The bailey was created by cutting a deep ditch across a high promontory, and the site commands good views over the Dysynni below. Tradition holds Cadwaladr ap Grufudd responsible for building Cynfael, sometime in the mid 1100's.

- Philip Davis

This site is a scheduled monument protected by law

Not Listed

The National Monument Record (Coflein) number(s)
County Historic Environment Record
OS Map Grid ReferenceSH614016
HyperLink HyperLink HyperLink

No photos available. If you can provide pictures please contact Castlefacts

Most of the sites or buildings recorded in this web site are NOT open to the public and permission to visit a site must always be sought from the landowner or tenant.

Calculate Print


  • Butler, L., 2009, 'The Castles of the Princes of Gwynedd' in Willams, D. and Kenyon, J. (eds), The Impact of the Edwardian Castles in Wales (Oxbow) p. 27-36
  • Morgan, Gerald, 2008, Castles in Wales: A Handbook (Talybont: Y Lolfa Cyf.) p. 241 (listed)
  • Davis, Paul R., 2007, Castles of the Welsh Princes (Y Lolfa) p. 47-8
  • Pettifer, Adrian, 2000, Welsh Castles, A Guide by Counties (Boydell Press) p. 120
  • King, D.J.C. with Kenyon, J.R., 2001, 'The Castles: a Study in Military Architecture' in Smith J.B. and Smith L.B. (eds), History of Merioneth Vol. 2 p. 411-12
  • Salter, Mike, 1997, The Castles of North Wales (Malvern) p. 49 (slight)
  • Davis, Paul R., 1988, Castles of the Welsh Princes (Swansea)
  • Avent, Richard, 1983, Castles of the Princes of Gwynedd (Cardiff)
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 278
  • Renn, D.F., 1973 (2 edn.), Norman Castles of Britain (London: John Baker) p. 162
  • RCAHMW, 1921, An inventory of the Ancient Monuments of Merionethshire (HMSO) p. 168 no. 535 online copy
  • Armitage, Ella, 1912, The Early Norman Castles of the British Isles (London: John Murray) p. 300 online copy
  • Lloyd, J.E., 1912, History of Wales (London) Vol. 2 p. 534n199 online copy
  • Lewis, Samual, 1849, A Topographical Dictionary of Wales online copy


  • Avent, Richard, 1994, 'Castles of the Welsh Princes' Château Gaillard Vol. 16 p. 11-17
  • Hogg, A.H.A. and King, D.J.C., 1963, 'Early castles in Wales and the Marches: a preliminary list' Archaeologia Cambrensis Vol. 112 p. 77-124
  • Clark, G.T., 1875, 'Moated mounds' Archaeologia Cambrensis Vol. 30 p. 66-7 online copy

Primary Sources

  • Brut y Tywysogion 1147 (Several transcriptions and translations exist the best being Jones, T., 1952, Brut Y Twysogion (University of Wales, History and Law series 11)–based on the Peniarth MS 20 version. There is a flawed translation Williams ab Ithel, John, 1860, Brut Y Twysogion or The Chronicle of the Princes (Rolls Series) online copy)