Juan de Villanueva was a prominent Spanish architect born in 1739 in Madrid. He is best known for his neoclassical style, which significantly influenced the architecture of Spain during the late 18th and early 19th centuries. Villanueva designed several important buildings, including the Museo del Prado and the Royal Observatory of Madrid. His work is characterized by its symmetry, simplicity, and use of classical elements. Villanueva's designs often incorporated large columns and open spaces, reflecting the ideals of the Enlightenment. He passed away in 1811, leaving a lasting legacy in Spanish architecture.