Layered defense and strategic location

The close relationship between the outer and inner works created the tactical trap at the center of a concentric castle. Attackers who gained part of the outer wall could still face plunging fire from the higher inner defenses, fire from untaken outer towers, and an immediate counterattack. Success at the first line could move an assaulting force from a bad position into a worse one unless it brought overwhelming firepower. The view across the Menai Strait also demonstrates why Beaumaris occupied a strong observation point for defending Anglesey and North Wales. Had Scotland or Ireland remained independent and periodically allied with France, later governments might have replaced the medieval outer wall with a modern artillery fort instead of leaving it intact.