Din Lligwy was a lightly fortified settlement, dating from the 3rd-4th century AD, probably inhabited by the Romano-British tribe. Despite the finds mainly from the Roman period, the beginnings of settlement in this area could go back to the Iron Age. Probably there was a small farming community at that time, dealing also with cattle breeding, for which the perimeter wall around the settlement was of greater importance as the protection of animals, than for purely military purposes. The tribe was also a craftsman, perhaps supplying Roman legions with iron tools and weapons, produced in their small workshops. The settlement functioned until around 385-400 CE, when it was abandoned. It was probably related to the withdrawal of the legions to Gaul.
A small settlement was founded on a plan of a pentagon, about 50 meters long on the east-west line. The perimeter wall was 1.2 to 1.5 meters thick and up to 2 meters high, made of stones not bonded with mortar, but well matched to each other.
The buildings placed in the courtyard had various shapes. There were two free-standing, round huts with a diameter of 6.5-7.3 meters and up to seven rectangular buildings. The largest of them were 14.7 by 5.7 meters. All but one were placed at the inner face of the perimeter wall of the settlement. Only a single rectangular building leaned against the south-west, outer façade of the wall, next to the original entrance, which was a simple gate pierced in the defensive perimeter. This building was probably connected with the service of the gate. Round structures were probably residential houses and rectangular ones were barns or workshops. There were more houses around the settlement to the north, south and west, where they stretched for 82 meters.
The foundations of buildings erected from local limestone have survived to this day. The peripheral defensive wall is also in good condition, although it is much smaller than its original height. The site is under the protection of the Cadw government agency, which makes it available to visitors.
Website anglesey-history.co.uk, The three ages of Lligwy.
Website coflein.gov.uk, Din Lligwy settlement, Moelfre.