Castell Trefadog
Has been described as a Possible Timber Castle (Other/Unknown)
There are earthwork remains
| Name | Castell Trefadog |
| Alternative Names | Porth Trefadog |
| Historic Country | Anglesey |
| Modern Authority | Anglesey |
| 1974 Authority | Gwynedd |
| Community | Llanfaethlu |
Very heavily-defended coastal site. Recent excavation revealed the foundations of C14 stone house inside an enclosure. An unusual site, perhaps akin to Penmaen Castle, Gower. Some have suggested a Viking origin for the site, others call it native welsh. Undergoing coastal erosion. In CARN listed as early medieval promontory fort, prehistoric coastal promontory fort and unknown fort.
A natural coastal knoll has been enhanced with a rampart and ditch to form a promontory fort. The knoll has been eroded by the sea on the north-west and north-east and only a near square area about 18m across remains of what may have been a rather larger enclosure. The 1.8m deep ditch on the south-east side takes advantage of a natural gully and on this side the rampart rises 3.4m from the ditch bottom. Slighter banks on the noth-east and north-west sides are probably old field boundaries. No finds are known from the site and its original date is unknown. It is perhaps most likely to be a later Prehistoric or Roman period fort. The traditional identification as a medieval earthwork castle ('Castell - site of': on OS County series 1st edition (Anglesey V.12 1889)) is perhaps unlikely. (Coflein–John Wiles 13.08.07)
A defended site with the sea on the N and W sides, a natural gully to the SE and a massive bank and ditch to the SW. The site has recently been excavated, and was shown to have comprised a level promontory defended by a bank, now surviving to a height of 2 m, inside a ditch 13 m wide and 4 m deep. The interior occupies some 250 sq. m, but some on the NW side has been lost through erosion of the cliff face. A large rectangular structure with rounded corners occupies the NW part of the interior. (Scheduling Report)
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 Reference | SH290859 |
| Latitude | 53.3422813415527 |
| Longitude | -4.56873989105225 |
| Eastings | 229080 |
| Northings | 385900 |
