Columbia subject headings:
Castles--Italy--Veneto.
Fortification--Italy--Veneto.
Veneto (Italy)--Defenses.
Harvard subject headings:
Castles--Italy--Veneto.
Fortification--Italy--Veneto.
Veneto (Italy)--Buildings, structures, etc.
Veneto (Italy)--Defenses.
Princeton subject headings:
Castles--Italy--Veneto.
Fortification--Italy--Veneto.