This is Spain's finest Islamic-era building outside Andalusia. It is still in use! Aragon's regional parliament has been housed here since 1987. Built as a fortified palace for Zaragoza's Islamic rulers (11th century), it underwent later alterations although it presesrves some of the best examples of Islamic art in Spain: the delicate interwoven arches of the central courtyard and the octogonal prayer room with its mihrab. This building is also World Heritage.