Din Lligwy is a late Iron Age example of a lightly-fortified farmstead or villa. The foundations and walls which are still well preserved, date from the fourth century. The site consists of nine buildings, two round and seven rectangular, all enclosed within a pentagonal low wall. Located near the edge of a low cliff or bluff, it provided a good view of visitors coming from the east. The two round structures were apparently domestic buildings, while the rectangular ones were workshops and for storage. Entrance to the complex was apparently through one of the rectangular buildings, which also served as a shed for animals. Within the larger of the two, archaeologists have found Roman coins, glass beads, a silver ingot and pottery fragments. In one of the "workshops" there are a number of hearths with ashes from oak and spatterings of metal slag, indicating that Iron was smelted there. The outer wall of the compound is made from a double layer of stone slabs with the center filled with rubble.

The interior structures are also well built, with the walls reaching six feet in some places. We can presume they were roofed with branches and covered in thatch. The main round house is slightly elevated, with two steps of stone slabs leading up to it. The entire enclosed area is slightly over a half-acre.