As far as Moorish buildings in Andalucia, the Alhambra in Granada is recognized as the most famous, but the Alcazar in Sevilla is a solid second. Since it is actually a group of palaces constructed over the ages, the complex is sometimes referred to as Los Reales Alcazares. The Alcazar is a UNESCO World Heritage Site and, like the Catedral, has quite an interesting history to it. The prominent site of the Alcazar has been occupied by a Roman acropolis, an early Christian basilica, a grouping of Visigoth buildings, and by Moorish palaces and fortresses.
The Almohads used the Alcazar as a citadel, and its fortifications stretched to the historic Torre del Oro along the Guadalquivir River. Only a few sections of the Almohad walls are left in the current Alcazar. What stands today is the so-called Christian remakes of the complex in a Mudejar architectural style that is a hybrid between Moorish and Spanish trends. Some portions of various Moorish buildings in Sevilla, Cordoba, and Valencia were removed and repositioned at the Alcazar. Various Spanish kings and queens commissioned entire wings, apartments, and extensive renovations to the complex. The royal apartments hosted Generalissimo Francisco Franco in his days in power. The Alcazar is still used as the official guest residence for the current royalty of Spain.
The most complete leftover from the Islamic period is the Patio del Yeso, the former Arabic palace. The surrounding Mudejar architecture does its best to mesh with the older parts. The main palace was rebuilt in the 14th century, with extensive enlargements and renovations tacked on over the centuries by the whims of the royals. The Puerta del Leon, the main gateway into the Alcazar, separates the Patio de la Monteria (hunting court) from the surrounding city. The main courtyard is the Patio de las Doncellas (maids' court). This connects with the Salon de los Embajadores (Hall of the Ambassadors), which features a golden dome. Perhaps the most important hall of the palace, this was where King Ferdinand and Queen Isabel supposedly welcomed Christopher Columbus after his triumphant return from the New World. This is part of a newer wing used to plot expeditions to the Americas. The Patio de las Munecas (court of the dolls) is one of the more delicately embellished spaces.
The Jardines del Alcazar (gardens) encompass a great deal of territory and reveals an eclectic mix of Arabic and European gardening styles. There are plenty of wonderful orange and lemon trees. Across the walls of the Alcazar are the Jardines de Murillo, which locals are free to enjoy at no cost.