Columbia subject headings:
Harvard subject headings:
Fortification, Roman--Great Britain--Guidebooks.
Fortification--Great Britain.
Great Britain--Antiquities, Roman--Guidebooks.
Great Britain--Antiquities, Roman.
Great Britain--Defenses.
Great Britain--History, Military--55 B.C.-449 A.D.
Great Britain--History--Roman period, 55 B.C.-449 A.D.
Romans--Great Britain
Princeton subject headings:
Fortification, Roman--Great Britain--Congresses.
Great Britain--Antiquities, Roman--Congresses.
Great Britain--Defenses--Congresses.
Great Britain--History--Roman period, 55 B.C.-449 A.D.--Congresses.
Romans--Great Britain--Congresses.