Columbia subject headings:
Harvard subject headings:
Fortification--Germany--Frankfurt am Main.
Frankfurt am Main (Germany)--Antiquities, Roman.
Germany--Antiquities, Roman.
Romans--Germany--Frankfurt am Main.
Princeton subject headings:
Frankfurt am Main (Germany)--Antiquities, Roman.
Frankfurt am Main (Germany)--Fortifications, military installations, etc.
Germany (West)--Antiquities, Roman.
Romans--Germany (West)--Frankfurt am Main.