Columbia subject headings:
Palaces--Spain--Madrid--History.
Palacio del Buen Retiro (Madrid, Spain)--History.
Retiro (Madrid, Spain)--History.
Harvard subject headings:
Palaces--Spain--Madrid--History.
Palacio del Buen Retiro (Madrid, Spain)--History.
Parks--Spain--Madrid--History.
Retiro (Madrid, Spain)--History.
Princeton subject headings:
Palaces--Spain--Madrid--History.
Palacio del Buen Retiro (Madrid, Spain)--History.
Retiro (Madrid, Spain)--History.