The Citadel (Al-Qalaa - usually pronounced "Al-'Alaa" presents the most dramatic feature of Cairo's skyline: a centuries-old bastion crowned by the needle-like minarets of the great Mosque of Mohammed Ali. The fortified complex was begun by Salah al-Din, the founder of the Ayyubid dynasty - known throughout Christendom as Saladin, the Crusaders' chivalrous foe. Salah al Din's reign (1171-1193 AD) saw much fortification of the city, though it was his nephew, Al Kamil, who developed the citadel as a royal residence, later to be replaced by the palaces of Sultan al-Nasir.

The main features of the Citadel are associated with Mohammed Ali, a worthy successor to the Mamlukes and Turks. In 1811 he feasted 470 leading Mamlukes in the Citadel palace, bade them farewell with honours, then had them ambushed in the sloping lane behind the Bab al-Azab, the locked gate opposite the Akhur Mosque. A painting in the Manial Palace on Roda Island depicts the apocryphal tale of a Mamluke who escaped by leaping the walls on his horse - in reality he survived by not attending the feast.

The Mohammed Ali Mosque is a little disappointing at close quarters. It has an ornate clock given by Louis Philippe in exchange for the obelisk in the Place de la Concorde, which has never worked; and the Turkish Baroque ablutions fountain, resembling a giant Easter egg. Inside the mosque, whose lofty dome and semi-domes are decorated like a Faberge egg, the use of space is classically Ottoman reminiscent of the great mosques of Istanbul. A constellation of chandeliers and globe lamps illuminates Thuluth inscriptions, a gold-scalloped mihrab and two minbars, one faced in alabaster, the other strangely Art Nouveau. Mohammed Ali is buried beneath a white marble cenotaph, behind a bronze grille on the right of the entrance. The mosque itself was erected between 1824 and 1848 although the domes had to be demolished and rebuilt in the 1930s.

Due south of here stands what remains of Mohammed Ali's Al-Gawhara Palace, where he waited while the Mamlukes were butchered. Also known as the Bijou (jewelled) Palace, its French-style salons exhibit portraits of the khedives and kings of Egypt and their wives; life-size models of monarchs and courtiers in nineteenth-century dress; royal furniture and tableware; and a collection of awful Impressionist works; the trompe l'oeil in the main salon is none too successful either. It was around here that Al Nasir's Striped Palace once stood, and that St Francis of Assisi preached to the Ayyubid ruler Al-Kamil. For many of the hapless boy-sultans chosen by the Mamlukes, the palace amounted to a luxury prison, and finally an execution cell. Nevertheless, the Citadel remained the residence of Egypt's rulers for nearly 700 years, and Mohammed Ali prophesied that his descendants would rule supreme as long as they resided here. Ismail's move to the Abdin Palace did indeed foreshadow an inexorable decline in their power.

There are many bastions along the Citadel's ramparts, each with evocative names. Although the derivation of Burg Kirkyilan (Tower of the Forty Serpents) is unknown, the Burg al-Matar (Tower of the Flight Platform) probably housed the royal carrier pigeons. A cluster of verdigris domes and a pencil-sharp minaret identify the Mosque of Suleyman Pasha as an early 16th century Ottoman creation, borne out by the lavish arabesques and rosettes adorning the interior of the cupola and semi-domes. Inside, cross the courtyard to find a mausoleum where the tombs of amirs and their families have tabuts indicating their rank - turbans or hats for the men, floral-patterned lingums for the women. Adjacent to the courtyard is a madrassa where students took examinations beneath a riwaq upheld by painted beams.