Columbia subject headings:
Arches--Spain.
Architecture--Spain.
Islamic architecture--Spain.
Harvard subject headings:
Alcazaba (Fortress : Málaga, Spain)
Aljafería (Zaragoza, Spain)
Arches
Arches--Spain.
Architecture--Spain
Catedral (Córdoba, Spain)
Islamic architecture--Spain
San Juan de Duero (Monastery : Soria, Spain)
Princeton subject headings: