Castell Bryngwyn Prehistoric Enclosure

The White Hill Castle, officially spelled Castell Bryngwyn, is a prehistoric site on the Isle of Anglesey. Despite some uncertainty in its early use, later Neolithic pottery indicates it was used during that period. The site is a circular clay and gravel bank covered with grass, still some 1.5 metres (4.9 ft) high and revetted externally by stone walls, which surround a level area some 54 metres (177 ft) in diameter. Although the exact purposes of the site are unclear, it is a recognized prehistoric site. During the Iron Age, the present wall was built, and it was rebuilt in Roman times. The site is accessible from the A4080 by a footpath. Other paths lead to the Bryn Gwyn stones or the former stone circle of Tre'r Dryw Bach. Remains of a Roman protection wall have also been found that may have been part of a larger fortification.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons