Columbia subject headings:
Besançon (France)--Defenses.
Fortification--France--Besançon--History.
Harvard subject headings:
Besançon (France)--Fortifications, military installations, etc.
Fortification--France--Besançon--History.
Princeton subject headings:
Besançon (France)--Buildings, structures, etc.
Fortification--France--Besançon--History.