Columbia subject headings:
Harvard subject headings:
Berlin (Germany)--History--18th century.
Berlin (Germany)--History--19th century.
Berliner Akzisemauer (Berlin, Germany)--History.
City walls--Germany--Berlin--History--18th century.
City walls--Germany--Berlin--History--19th century.
Gates--Germany--Berlin--History--18th century.
Gates--Germany--Berlin--History--19th century.
Princeton subject headings:
Berlin (Germany)--Buildings, structures, etc.
Berlin (Germany)--Description and travel.
Berliner Akzisemauer (Berlin, Germany)