Beaumaris Castle, built between 1272 and 1307 on the island of Anglesey in North Wales, is considered one of the finest examples of medieval military architecture in Britain. Designed by Master James of St Georges for Edward I as the final fortress in the 'iron ring' of Welsh castles, it features innovative concentric design with round towers, inner and outer circuit walls, massive towered gates, and a fortified dock. Although left unfinished due to funding constraints and Scottish troubles, it remains a UNESCO World Heritage Site alongside Conwy, Harlech, and Caernarfon, representing the pinnacle of medieval defensive sophistication.
