Juan de Herrera was a Spanish architect and engineer born in 1530. He is best known for his work on the Escorial, a massive royal palace and monastery located near Madrid. Herrera's design combined Renaissance and Mannerist styles, showcasing his innovative approach to architecture. In addition to the Escorial, Herrera contributed to various other projects, including bridges and fortifications. He served as the chief architect for the Spanish crown and was influential in the development of Spanish architecture during the late 16th century. His work remains significant in the history of Spanish architecture.