Carn Fadryn

Has been described as a Certain Timber Castle (Other/Unknown), and also as a Certain Masonry Castle

There are masonry ruins/remnants remains

NameCarn Fadryn
Alternative NamesGarn Fadryn; Carn Fadrun; Madryn; Garn Fadrun
Historic CountryCaernarfonshire
Modern AuthorityGwynedd
1974 AuthorityGwynedd

Crowning the summit of Carn Fadrun, a prominent mountain on the Llyn peninsula, are the remains of an Iron Age hillfort and medieval castle. The hillfort appears to be of two phases - the first phase enclosing an area roughly 4.8ha in extent and defined by a ruinous rampart wall with entrances to the north and south. The second phase fort enclosed a much larger area, encompassed the first phase fort together with land to the north and south, some 10.7ha. It is defined by a better preserved rampart circuit, again with entrances to the north and south. The interior of the fort shows many tumbled stone-walled buildings, some round, some rectangular and some irregular. Some have small walled yards or gardens attached. Similar features are scattered thickly over the steep slopes below the ramparts and may well represent activity here from the Iron Age through to the Roman period and possibly later. The medieval castle crowns the highest part of the summit, on the edge of a precipitous fall to the west. Here a narrow platform of rock was utilised as a readymade motte. The ruins of the castle comprise of a narrow loop of drystone wall forming an enclosure below the rocky knoll summit. There are no traces of any internal buildings surviving

Carn Fadrun was mentioned by Gerald of Wales as newly built in 1188, and it forms part of a small cluster of early stone-built castles constructed in Gwynedd at the end of the twelfth century, together with Castell Aber Ia (Castell Deudraeth) Dinas Emrys Tomen Castell and Castell Pen-y-garn These were not placed to withstand alien invasion, but were rather an expression of a Prince's power and lordship in the unsettled period following the death of Owain Gwynedd in 1170 and the subsequent division of the county between his sons. (Coflien–Louise Barker, RCAHMW, 5th June 2008)

The top of the hill is defended by the remains of two strong stone walls, probably representing two periods of the pre-Roman fortification, a smaller fort of about 12 acres having been succeeded by a larger of about 26 acres. These defences are probably to be associated with the stone hut-circles which occur on the hill. In addition to these round buildings there are numerous small huts of irregular shape cut into the ruins of the earlier rampart, and associated with irregular enclosures. The highest part of the W ridge has been made into a construction of a stone wall. In addition to the huts within the early defences, numerous round and irregular foundations, some with enclosures, occur on the slopes of the hill. In absence of excavation the analysis of the remains rest on their surface appearance (RCAHMW 1964).

Iron Age settlement site referred to in 'Ancient Britain' map as Garn Fadron.

Very impressive site. The greater part of the interior had been burnt of its heather and bilberry plant cover, with the result that features were very clear. However, little if anything be seen that is not on RCAHM's published plan (Kelly, R. S. , 1986 , Site Visit). (Gwynedd Archaeological Trust HER)

The monument comprises the remains of a Hillfort on a high rocky hill, with steep scree slopes. The top is defended by the remains of two strong stone walls which form an inner fort of twelve acres and a larger fort of 26 acres. At the summit are the remains of a small stronghold which is reputed to be the 12th C castle of the 'Sons of Owain' mentioned by Giraldus Cambrensis. The interior of the fort contains large numbers of stone huts with associated enclosures; there are also huts built outside the fort on the steep slopes of Garn Fadryn. The scheduled area includes the settlement remains on Garn Bach in addition to the fortified remains on Garn Fadryn. (Scheduling Report)

Gatehouse Comments

Here the rudimentary stone buildings are ringed by a low wall more reminiscent of Iron Age hillforts than the new Norman motte and bailey design. The remains comprise a great number of 'house' structures, of a variety of forms, from round to rectangular, associated with 'yards', lanes and terraced ways. Whilst some appear to be contemporary with the fort, others overlie its wreck. A small 'summit fort', c.100m N-S by 30m, thought to be a castle, newly built in 1188. It is clear that the fort represents only an episode in the sequence of occupation apparent at this location.

- 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 ReferenceSH280352
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  • Davis, Paul, R., 2011, The Forgotten Castles of Wales (Almeley: Logaston Press) p. 52-54
  • 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
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  • Pettifer, Adrian, 2000, Welsh Castles, A Guide by Counties (Boydell Press) p. 24-5
  • Salter, Mike, 1997, The Castles of North Wales (Malvern) p. 25
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  • Fry, P.S., 1980, Castles of the British Isles (David and Charles)
  • Renn, D.F., 1973 (2 edn.), Norman Castles of Britain (London: John Baker) p. 194
  • RCAHM, 1964, ‘Cam Fadrun’, in A Survey and Inventory of the Ancient Monuments of Caernarvonshire Vol. 3, West (HMSO) p. 69-71 no. 1650 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., 1967, 'Masonry castles in Wales and the Marches: a list' Archaeologia Cambrensis Vol. 116 p. 71-132
  • 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
  • Morris, T.E., 1927, 'The Castle of Deudraeth' Archaeologia Cambrensis Vol. 82 p. 355

Primary Sources