Built at the end of the 16th century on a plan in the form of a grill, the instrument of the martyrdom of St Lawrence, the Escurial Monastery stands in an exceptionally beautiful site in Castile. Its austere architecture, a break with previous styles, had a considerable influence on Spanish architecture for more than half a century. It was the retreat of a mystic king and became, in the last years of Philip II's reign, the centre of the greatest political power of the time.