The Prince of Wales Royal Regimental Museum (Northern building) which is located on the northern side of the inner bailey, to the west of Arthurs Hall was constructed in the 1740s as accommodation for enlisted men within the barracks, as a response to a perceived threat to Britain from the continent. It appears to have been built upon a ruinous medieval single-storey building which may have been a part of the ‘Old Hall’ that dates from the reign of King John (1199-1216). (location accurate to the nearest 1m based on available information)