Columbia subject headings:
Architecture--England--London.
Buildings--England--London Zoo (London)
London Zoo (London, England)--History.
Harvard subject headings:
Architecture--England--London
London Zoo (London, England)--Buildings, structures, etc.
London Zoo (London, England)--History.
Princeton subject headings:
London (England)--Buildings, structures, etc.
London Zoo (London, England)--Buildings.
London Zoo (London, England)--History.
Park buildings--England--London.