Dolbenmaen Castle

Has been described as a Certain Timber Castle (Motte), and also as a Certain Masonry Castle, and also as a Palace (Other)

There are earthwork remains

NameDolbenmaen Castle
Alternative NamesTomen; Plas Dolbenmaen
Historic CountryCaernarfonshire
Modern AuthorityGwynedd
1974 AuthorityGwynedd

A medieval castle mount thought to have been associated with a llys, a princely court. This is a steep sided roughly circular mound, roughly 40m across and 6.5m high. The 12.5-14.5m diameter summit is dished within a slighly raised bank. There is a broad ditch on the west of the mound which is otherwise encroached upon and multilated by the outbuildings of the Plas on the north and east. With the exception of the thirteenth century castle of Criccieth this is the only castle site in Eifionydd cantref. It is possible that Plas Dolbenmaen, recorded in 1662, at the foot of the mound, stands on the site of a medieval house. St Mary's church (NPRN 43776)could have originated as a chapel attached to a llys. There are several instances in north Wales of castle mounds associated with apparently unfortified houses, for example Aber (NPRN 95692), also in Caernarvonshire, and Castell Prysor (NPRN 308964), Crogen (NPRN 306558) and Rug (NPRN 306598) in Merioneth. (Coflein)

Dolbenmaen motte stands on a low ridge running parallel to the river Dwyfor at a fordable crossing point on an important routeway. Its architects may have been Norman or Welsh and its early history is uncertain. Later it formed the maerdref (administrative centre) of the commote of Eifionnydd and is thought to have been one of the royal residences of the Welsh Princes until it was abandoned by Llywelyn Fawr around 1230 in favour of the newly constructed Criccieth Castle. The motte itself is 36m in diameter and about 6m high. Some loose masonry is all that remains to indicate the presence of any buildings on the flattened top of the mound. The possible site of a bailey, if one existed, is now covered by farm buildings and Plas Dolbenmaen which itself dates to the 16th to 18th centuries. The 15th century parish church of St. Mary's stands directly opposite the motte. The mound stands on a low ridge running E-W parallel to the river and forming a natural approach to a crossing

The ridge ends is a tongue occupied by a house and farm buildings which may cover the site of a bailey. The mound is 6.6m high. The E half has been mutilated and the lower slopes are cut into by farm buildings. The ditch, 1.3m deep, remains on the W side. The summit 14.6m by 12.6m is hollowed and now surrounded by a slightly raised bank. Loose stones suggest that masonry buildings once occupied the top. The seat of the princes of Eifionydd, later Cricieth, may formerly have been here. (Gwynedd Archaeological Trust HER)

Castle mound, 36m in diameter and some 6m high. A substantial ditch survives on the west, but on the other sides the base has been damaged by later walls. Had there been a bailey, it has been lost under later buildings. The history of the motte, built at a fordable crossing of the river Dwyfor, is not well documented. It could be a Norman base or the product of the revival of Welsh power in the early C12. It later formed the administrative center maerdref of the commote of Eifionydd and a royal seat until about 1230, when Llywelyn the Great moved the court to Criccieth. (Lynch)

A motte built by the side of the Afon Dwyfor, part of which has been destroyed by the farmhouse and buildings which lie on the W side. It stands about 6 m high and is 36 m in diameter at the base. The top measures 8 m N - S and 11 m W - E. A masonry wall 0.75 - 1 m high encircles the top. The area inside this wall has been damaged by trees which have grown and subsequently fallen, creating large holes. The same thing has happened on the sides of the motte. The ditch, visible on the S and W sides, is between 0.75 and 1 m deep, and about 7 m wide. (Scheduling Report)

Gatehouse Comments

The form of the mound may suggest this was originally a mound reveted with near vertical timber walls as at South Mymms, Herts.

- 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 ReferenceSH506430
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  • Morgan, Gerald, 2008, Castles in Wales: A Handbook (Talybont: Y Lolfa Cyf.) p. 233 (listed)
  • Pettifer, Adrian, 2000, Welsh Castles, A Guide by Counties (Boydell Press) p. 36
  • Salter, Mike, 1997, The Castles of North Wales (Malvern) p. 49 (slight)
  • Lynch, Frances, 1995, A Guide to Ancient and Historical Wales: Gwynedd (HMSO)
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 34
  • RCAHMW, 1960, A Survey and Inventory of the Ancient Monuments of Caernarvonshire Vol. 2: Central (HMSO) p. 74 no. 916 online copy
  • Lewis, Samual, 1849, A Topographical Dictionary of Wales online copy


  • 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
  • Owen, Edward, 1903, 'Ancient British camps, etc., in Lleyn, co. Carnarvon' Archaeologia Cambrensis Vol. 58 p. 258 online copy