Columbia subject headings:
Harvard subject headings:
Architecture, Medieval--Spain--Avila (Province)
Avila (Spain : Province)--Buildings, structures, etc.
Fortification--Spain--Avila (Province)
Towers--Spain--Avila (Province)
Princeton subject headings:
Architecture, Medieval--Spain--Avila (Province).
Avila (Spain : Province)--Buildings, structures, etc.
Fortification--Spain--Avila (Province).
Towers--Spain--Avila (Province).