Columbia subject headings:
Harvard subject headings:
Excavations (Archaeology)--Great Britain
Fortification, Roman--Great Britain.
Great Britain--Antiquities, Roman.
Great Britain--History, Military--55 B.C.-449 A.D.
Romans--Great Britain
Rome--Military antiquities
Princeton subject headings:
Fortification, Roman--Great Britain.
Great Britain--Antiquities, Roman.
Romans--Great Britain.