"My name is Brian. My builders were princes, and I am located close to a famous Welsh town (as the crow flies, that is). I was fortified long before the age of the castle and overlook the home of two famous ladies. What castle am I and can you explain my riddle?"
Yes, the correct answer is CASTELL DINAS BRAN!
The ruins of Castell Dinas Bran rest peacefully 800 feet above the Welsh town of Llangollen overlooking the beautiful Dee Valley. In the Welsh language "Bran" is often translated as "Brian" and Dinas Bran is alternately known as "crow castle". There is evidence that an Iron Age hillfort occupied the site long before the 13th century medieval castle was built by the princes of Powys. In the town of Llangollen you'll find "Plas Newydd" the magnificently-carved Tudor home of the "Ladies of Llangollen" the town's famous spinsters. Nearby lie the evocative ruins of Valle Crucis Abbey.