Columbia subject headings:
Castles--Italy--Otricoli.
Fortification--Italy--Otricoli.
Rocca di Otricoli (Italy)
Harvard subject headings:
Princeton subject headings:
Castles--Italy--Otricoli--History.
Fortification--Italy--Otricoli--History.
Otricoli (Italy)--Buildings, structures, etc.
Otricoli (Italy)--History.
Rocca di Otricoli (Otricoli, Italy)