The large Renaissance palace of Charles V adjoining the Patio de Comares was designed by Pedro Machuca. He built the Puerta de las Granádas (ca. 1546) as a formal Renaissance entrance to the Alhambra precinct. The construction of the palace began in 1533; the design was revised by Juan de Herrera, and work continued for over a century, but the palace was never completed. Perhaps the finest Renaissance palace in Spain, it has a square plan and a circular courtyard.