The unfinished fortress

King Edward I conquered North Wales in the 1200s, then built a ring of castles around it to defend his newly won territory. Beaumaris Castle is one of them—or, to be more accurate, nearly one of them. Before construction on Beaumaris was completed, the king's finances and attention were redirected to his military campaign in Scotland. The stout fortress was never fully finished—but the concentric design of walls within walls has been praised by historians as a triumph of medieval military architecture.