Technically the oldest European royal residence still in use (the king and queen stay here when they’re in Sevilla), this complex of palaces and fortifications dates from the Almohad rule of Sevilla. It was, however, almost entirely rebuilt after the 1248 reconquest of Sevilla. The older, more austere building is the Palacio Gótico, built by Alfonso X (“the Wise”) in the 13th century. Carlos V modified the Great Hall and the Sala de Fiestas to celebrate his 1526 wedding to his Habsburg cousin (an unfortunate union that triggered the genetic problems of the dynasty). The far more beautiful and much larger Palacio Mudéjar was built in the 14th century by Pedro I (“the Cruel”), likely employing some of the same artisans who worked on the Alhambra in Granada. It’s a tour de force of carved plaster and stone, delicate calligraphic friezes, carved wooden ceilings, and splendid decorative tiles. From the Dolls’ Court to the Maidens’ Court through the domed Ambassadors’ Room, it contains some of the finest work of Sevillano artisans. Fernando and Isabel, who at one time lived in the Alcázar, welcomed Columbus here on his return from America. On the top floor, the Oratory of the Catholic Monarchs has a fine altar in polychrome tiles made by Pisano in 1504. The well-kept gardens are alone worth the visit. Plan to spend about 1 1/2 hours here.