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Twthill, Caernarfon

In the community of Caernarfon.
In the historic county of Caernarfonshire.
Modern authority of Gwynedd.
Preserved county of Gwynedd.

OS Map Grid Reference: SH48246305
Latitude 53.14269° Longitude -4.27087°

Twthill, Caernarfon has been described as a Timber Castle although is doubtful that it was such.

There are uncertain remains.


A probable pre-Roman defended ditch is represented by traces of a rock cut ditch on the summit. However, this looks uncertain and it may possibly have been some form of motte and bailey (Source: OS 495 card). (Coflein–M.Edwards, RCAHMW, 19 October 2001)

A probable pre-Roman 'defended post' on Twthill is represented by the traces of a rock-cut ditch near the summit (Smith). A bank of earth 10ft wide and 4ft high runs in a slight curve from NW to SE across the flat top of the ridge that extends NE from Twthill. Its purpose is uncertain but it does not appear to be defensive. Condition - fair (RCAHMW). The summit of Twthill has a fairly flat and level rock surface which measures 40m E-W by 25m N-S. It bears no traces of occupation but it is ideally suited for since steep rock faces fall sharply on all sides of plateau. There is no indication that the ditch has been artificially cut. The bank is not defensive in itself. Allowing for the curve of the ridge it seems that the bank forms an arc based on the summit of Twthill, and it seems designed to serve some purpose closely associated with the hill. It is unlikely to have been a crude form of hill fort (OS Record). (Gwynedd Archaeological Trust HER)

A naturally defensive site that could have been used in any period as a retreat and look out but there is no evidence to actual support it being so used. For medieval knights, dependent upon horses, the lack of water would make this an unfavourable site and the least likely occupation of the site is as a medieval 'motte and bailey'.
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This record last updated before 1 February 2016