Columbia subject headings:
Castles--England.
Castles--Wales.
Great Britain--History--1066-1687.
Harvard subject headings:
Architecture and society--Great Britain.
Architecture, Medieval--Great Britain.
Castles--England
Castles--England--History--To 1500.
Castles--Wales
Castles--Wales--History--To 1500.
Great Britain--History--1066-1687.
Princeton subject headings:
Castles--England.
Castles--Wales.
Great Britain--History--1066-1687.