Interesting article on the three ages of Lligwy at this website.
It seems that excavations indicate that the site was in use many years before the roman occupation.
When I visited the site, it had the same feel as an abbey. The people who built the walls and the houses went to a great deal of effort. The walls, and stones are massive.
The place is an enigma, I don't think we understand the real story of its construction or its use.
Something is not right. This message is just to keep things from messing up down the road