Tomen Fawr, Llanystumdwy

Has been described as a Certain Timber Castle (Ringwork)

There are earthwork remains

NameTomen Fawr, Llanystumdwy
Alternative NamesDolwydln; Domen Fawr; Llanystwmdwy; Glan-llynau
Historic CountryCaernarfonshire
Modern AuthorityGwynedd
1974 AuthorityGwynedd

A ring motte situated on the edge of a ridge of clay drift, 400m from the sea. The interior, 12m in diameter has been partly filled in by the collapse of the bank. The N of the interior is overgrown with gorse, broom and bramble. The top of the bank is between 2 and 4 m above the interior, although this diminishes to 0.5m on the S edge, where part of the bank may have collapsed outward (see RCAHM description). The bank is 2m wide at the top. The encircling ditch is best preserved on the north and the east where it is 4m below the crest of the bank. On the north the ditch has been partly been filled in, although it is still visible. On the south the site is defended by the natural slope, although this has been dug into to create material for the bank, which resulted in the line of the ditch being continued round the monument. There are no obvious archaeological features outside the line of the ditch, although the field below the slope to the south of the site does contain a number of amorphous humps. (Gwynedd Archaeological Trust HER)

Gatehouse Comments

This small ringwork presumably represents a farmstead held by military service.

- 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 ReferenceSH454376
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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)
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 35
  • RCAHMW, 1960, A Survey and Inventory of the Ancient Monuments of Caernarvonshire Vol. 2: Central (HMSO) p. 237-8 no. 1374 online copy


  • King, D.J.C. and Alcock, L., 1969, 'Ringworks in England and Wales' Ch√Ęteau Gaillard Vol. 3 p. 90-127
  • 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