The eastern half of Cairo is divided into many quarters. These quarters were formerly closed at night by massive gates. A few of these gates remain. In addition to the Mahommedan quarters, usually called after the trade of the inhabitants or some notable building, there are the Copt or Christian quarter, the Jews' quarter and the old "Frank" quarter. The last is the Muski district where, since the days of Saladin, "Frank" merchants have been permitted to live and trade. Some of the principal European shops are still to be found in this street. The Copt and Jewish quarters lie north of the Muski. The Coptic cathedral, dedicated to St Mark, is a modern building in the basilica style. The oldest Coptic church in Cairo is, probably, the Keniset-el-Adra, or Church of the Virgin, which is stated to preserve the original type of Coptic basilica. The Coptic churches in the city are not, however, of so much interest as those in Old Cairo (see below). In the Copt quarter are also Armenian, Syrian, Maronite, Greek and Roman Catholic churches. In the Copt and Jewish quarters the streets, as in the Arab quarters, are winding and narrow. In them the projecting upper stories of the houses nearly meet. Sebils or public fountains are numerous.
These fountains are generally two-storeyed, the lower chamber enclosing a well, the upper room being often used for scholastic purposes. Many of the fountains are fine specimens of Arab architecture. While the houses of the poorer classes are mean and too often dirty, in marked contrast are the houses of the wealthier citizens, built generally in a style of elaborate arabesque, the windows shaded with projecting cornices of graceful woodwork (mushrebiya) and ornamented with stained glass. A winding passage leads through the ornamental doorway into the court, in the centre of which is a fountain shaded with palm-trees. The principal apartment is generally paved with marble; in the centre a decorated lantern is suspended over a fountain, while round the sides are richly inlaid cabinets and windows of stained glass; and in a recess is the divan, a low, narrow, cushioned seat. The basement storey is generally built of the soft calcareous stone of the neighbouring hills, and the upper storey, which contains the harem, of painted brick. The shops of the merchants are small and open to the street. The greater part of the trade is done, however, in the bazaars or markets, which are held in large khans or storehouses, of two storeys and of considerable size.
Access to them is gained from the narrow lanes which usually surround them. The khans often possess fine gateways. The principal bazaar, the Khan-el-Khalil, marks the site of the tombs of the Fatimite caliphs.
Besides the citadel, the principal edifices in the Arab quarters are the mosques and the ancient gates. The citadel or El-Kala was built by Saladin about 1166, but it has since undergone frequent alteration, and now contains a palace erected by Mehemet Ali, and a mosque of Oriental alabaster (based on the model of the mosques at Constantinople) founded by the same pasha on the site of "Joseph's Hall," so named after the prenomen of Saladin. The dome and the two slender minarets of this mosque form one of the most picturesque features of Cairo, and are visible from a great distance. In the centre is a well called Joseph's Well, sunk in the solid rock to the level of the Nile. There are four other mosques within the citadel walls, the chief being that of Ibn Kalaun, built in A.D. 1317 by Sultan Nasir ibn Kalaun. The dome has fallen in. After having been used as a prison, and, later, as a military storehouse, it has been cleared and its fine colonnades are again visible. The upper parts of the minarets are covered with green tiles. They are furnished with bulbous cupolas. The most magnificent of the city mosques is that of Sultan Hasan, standing in the immediate vicinity of the citadel.
It dates from A.D. 1357, and is celebrated for the grandeur of its porch and cornice and the delicate stalactite vaulting which adorns them. The restoration of parts of the mosque which had fallen into decay was begun in 1904. Besides it there is the mosque of Tulun (c. A.D. 879) exhibiting very ancient specimens of the pointed arch; the mosque of Sultan El Hakim (A.D. 1003), the mosque el Azhar (the splendid), which dates from about A.D. 970, and is the seat of a Mahommedan university; and the mosque of Sultan Kalaun, which is attached to the hospital or madhouse (muristan) begun by Kalaun in A.D. 1285. The whole forms a large group of buildings, now partially in ruins, in a style resembling the contemporaneous medieval work in Europe, with pointed arches in several orders. Besides the mosque proper there is a second mosque containing the fine mausoleum of Kalaun. Adjacent to the muristan on the north is the tomb mosque of al Nasir, completed 1303, with a fine portal. East of the Khan-el-Khalil is the mosque of El Hasanēn, which is invested with peculiar sanctity as containing relics of Hosain and Hasan, grandsons of the Prophet. This mosque was rebuilt in the 19th century and is of no architectural importance.
In all Cairo contains over 260 mosques, and nearly as many zawias or chapels. Of the gates the finest are the Bab-en-Nasr, in the north wall of the city, and the Bab-ez-Zuwēla, the only surviving part of the southern fortifications.