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