"I was the last of my kind and am found in a land of ancient Druids and holy saints. Some say I'm perfect while others lament that I never reached my full potential. What castle am I and can you explain my riddle?"
Yes, the correct answer is BEAUMARIS CASTLE!
Beumaris, begun in 1295, was the last of the great Edwardian castles built in north Wales. The castle is located on the Isle of Anglesey with its ancient traditions of druids, Celtic holy men and saints. Many feel that Beaumaris is a perfect example of the concentric-style of castle. Unfortunately the castle was never completed as originally planned, making Beaumaris something of an unfinished masterpiece.