Columbia subject headings:
Harvard subject headings:
Architecture, Medieval--Italy--Volterra.
Architecture--Italy--Volterra.
Plazas--Italy--Volterra.
Volterra (Italy)--Buildings, structures, etc.
Princeton subject headings:
Historic buildings--Italy--Volterra.
Piazza dei Priori (Volterra, Italy)
Plazas--Italy--Volterra.
Volterra (Italy)--Buildings, structures, etc.