Castell Bryn Gwyn, officially spelled Castell Bryngwyn, is a prehistoric site on the Isle of Anglesey, west of Brynsiencyn. It is a circular clay and gravel bank covered with grass, still some high and revetted externally by stone walls, which surround a level area some in diameter.
Its name means "White Hill Castle". Since 2024, Cadw, who maintain the site, use the spelling "Bryngwyn".
Prehistoric origins The original use of this site is uncertain although it may have been a religious sanctuary. Later Neolithic pottery indicates use in this period, and it may have been a henge monument at this time. The earliest bank and ditch belong to the end of the Neolithic period (2500-2000 BC).Cadw sign at the site
Roman invasion During the Iron Age, the present wall was built, and it was rebuilt in Roman times and later.Cyfeillion Ymddiriedolaeth Archaeolegol Gwynedd, Haf 2009. Friends of the Gwynedd Archaeological Trust, Summer 2009. Prehistoric Funerary and Ritual Survey, pp 32-33
Access Car parking is minimal but the site is accessible from the A4080 by a footpath. Another path follows the low ridge, southwest over stiles to the Bryn Gwyn stones, or northeast, past the site of the former stone circle of Tre'r Dryw Bach, some to Caer Lêb where it meets a minor road with limited car parking space.
See also List of hillforts in Wales
References