Columbia subject headings:
Castello Colonna (Castelnuovo di Porto, Italy)
Castelnuovo di Porto (Italy)--Buildings, structures, etc.
Castles--Conservation and restoration--Italy--Castelnuovo di Porto.
Harvard subject headings:
Castello Colonna (Castelnuovo di Porto, Italy)
Castelnuovo di Porto (Italy)--Buildings, structures, etc.
Castles--Conservation and restoration--Italy--Castelnuovo di Porto.
Princeton subject headings:
Castello Colonna (Castelnuovo di Porto, Italy)
Castelnuovo di Porto (Italy)--Buildings, structures, etc.
Castles--Conservation and restoration--Italy--Castelnuovo di Porto.