No ordinary park, Parque del Buen Retiro is a 350-acre expanse of green that was once the private preserve of the Spanish kings and queens. What they left behind, aside from some stunning gardens and topiary, is a legacy of architectural showpieces in the heart of Madrid: the boating pond is watched over by the colonnade of the Monumento de Alfonso XII on one side, while the Palacio de Cristal, an imposing glass palace modeled on London’s Crystal Palace, lies hidden among the trees on the other. In the northeastern corner of the park are the 13th Century Romanesque ruins of a hermitage, while the southwestern corner is home to the poignant Bosque de los Ausentes, an olive and cypress memorial to the victims of the March, 2004 train bombings. Near Rosaleda, the formal expanse of rose gardens, is the reason I ventured into the park in the first place: the fountain of The Fallen Angel, El Angel Caido. Surrounded by a phalanx of water-spouting serpents it must be one of the only – if not the only statue – dedicated to Lucifer.