Columbia subject headings:
Cologne (Germany)--Antiquities, Roman.
Excavations (Archaeology)--Germany--Cologne.
Maps.
Romans--Germany--Cologne.
Waterworks--Germany--Cologne--Maps.
Waterworks--Germany--Cologne.
Harvard subject headings:
Aqueducts--Germany--Cologne.
Waterworks--Germany--Cologne.
Princeton subject headings:
Aqueducts--Germany (West)--Cologne Region--Atlases.
Cologne Region (Germany)--Antiquities, Roman.
Germany (West)--Antiquities, Roman.