Columbia subject headings:
Architecture, Roman--Italy--Herculaneum (Extinct city)
Herculaneum (Extinct city)--Buildings, structures, etc.
Harvard subject headings:
Herculaneum (Extinct city)--Buildings, structures, etc.
Princeton subject headings:
Architecture--Italy--Herculaneum (Extinct city).
Herculaneum (Extinct city)--Buildings, structures, etc.
Walls--Italy--Herculaneum (Extinct city).