The Monastery of El Escorial,
located some 30 miles northwest of Madrid in the foothills of the Sierra de Guadarrama,
was built as a monument to commemorate the Spanish victory over the French
in the battle of Saint Quentin on 10 August 1557 (feast day of St. Lawrence).
Felipe II himself selected the site for the monastery,
1,028 meters (3,372 feet) above sea level, and personally oversaw the progress of the project.
The monastery was initially designed by architect Juan Bautista de Toledo,
but after his death in 1567, his assistant Juan de Herrera continued the work.
Construction lasted 21 years from 1563 to 1584,
and for many years after its completion,
El Escorial Monastery was the largest building in the world.