Castell Trefadog

1. Anglesey Inventory (1937)

CASTELL, situated on the coast at Porth Trefadog, about 1m. S.W. of the church. The site consists of a small natural knoll of moraine gravel, with the sea on two sides and fortified on the landward side with a large ditch and bank, making in effect a small promontory fort. The defences are partly conditioned by a natural gully on the S.E. side; it is probable that the natural slopes of the knoll along this gully have been artificially scarped and a bank has been built on the upper edge. Across the ground to the S. and S.W. of the knoll is a ditch 35-40 ft. wide and now 6 ft. deep, the soil from which has been piled on to the knoll to make a massive rampart. At its E. end the ditch curves and dies into the gully; on the W. it ends at the cliff. Along the seaward edge of the knoll are low grass-grown banks, probably modern field-walls. The site has been considerably eroded by the sea and the defended area must have been originally larger than at present. (See p. lxx.) Condition—Fair, but eroded by sea.

RCAHMW (M). 1937. An Inventory of the Ancient Monuments in Anglesey. HMSO, London. Pp. 68-9.

2. Gwynedd Archaeological Trust (PRN 1):

A heavily defended promontory on the north west coast of Anglesey, now protected as an ancient monument of national importance. The site was excavated by D. Longley in 1984-5 and was found to consist of a massive defensive bank and ditch on the landward side, enclosing an area of some 250 square metres. The foundations of a large 14th century house were revealed within the enclosure, which was later used as a metal working site. Finds included a bronze fastener, metal working debris and a single sherd of samian pottery.

Selected references:

Longley, D. , 1984 , Castell, near Trefadog Farm, Llanfaethlu , Archaeology in Wales : Vol. 24 : p.76

Longley, D. , 1991 , Medieval Archaeology

3.Recorded during Royal Commission aerial survey.

Toby Driver, RCAHMW, 2024

Site Record

Castell Trefadog, early medieval coastal promontory fort