Twyn Llewelyn Mound A

Has been described as a Rejected Timber Castle (Motte)

There are earthwork remains

NameTwyn Llewelyn Mound A
Alternative Names
Historic CountryGlamorgan
Modern AuthorityVale of Glamorgan
1974 AuthoritySouth Glamorgan

One of two mounds in salt marsh by River Thaw. One or both have previously been suggested as fortifications but Lewis concluded these were navigational markers. (Spurgeon)

An irregular circular mound, around 16m in diameter and 1.7m in height. It was composed of stone and earth. However, the mound has been destroyed by the making of a new river channel for the Thaw. (Glamorgan-Gwent Archaeological Trust HER as medieval earthwork)

J. Lewis examined this mound for the Ministry of Works before it was destroyed by the making of a new channel for the River Thaw for a new power station. The mound was largely composed of natural rock, but with a cairn on top. It probably marked the channel of the River Thaw during high tide. No finds were recorded. (Med. Arch.)

Not scheduled

Not Listed

County Historic Environment Record
OS Map Grid ReferenceST031664
HyperLink HyperLink HyperLink

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

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  • Spurgeon, C.J. with Roberts, D.J. and Thomas, H.J., 1999, 'Supposed Castles in Glamorgan; A review' Archaeology in Wales Vol. 39 27-40
  • Hurst, J,G, (ed), 1957, 'Twyn Llewlyn, Aberthaw' Medieval Archaeology Vol. 1 p. 170 download 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 (reject)


  • Dunning, R. and Howell, J., 2005, Waterfronts in southeast Wales