The Sultan al-Nasir Muhammad ibn Qala'un Mosque is an early 14th century mosque at the Citadel in Cairo, Egypt (the sultan also built a religious complex in the center of the city, next to the one by his father Qalawun). It was built by the Mamluk sultan Al-Nasr Muhammad in 1318 as the royal mosque of the Citadel, where the sultans of Cairo performed their Friday prayers. The mosque is located across the street from the courtyard access to the Mosque of Muhammad Ali.
The hypostyle mosque is built as a free standing 63 x 57 m rectangle around an inner court with a sanctuary on the qibla side and galleries surrounding the other three sides. The main entrance protrudes from the face of the western wall. There are two other entrances, on the northeastern side and on the southern side, respectively. Unlike most other mosques of Cairo, its outer walls are not paneled and have no decoration except a crenellation composed of rectangles with rounded tops. This results in a rather austere appearance which is probably accounted for by the military nature of its setting. Crenellation on the inner walls around the courtyard is of the stepped type.
There are two minarets, both built entirely of stone, one at the northeast corner and one at the northwest portal right above the main entrance; the former is the higher of the two. The top of the latter is unique in Cairo in that it has a garlic-shaped bulb. The upper structure is covered with green, white and blue glazed mosaics (faience). This style has probably been brought by a craftsman from Tabriz who is known to have come to Cairo during the reign of al-Nasr Muhammad. Contrary to all other Mamluk mosques, the base of both minarets is below the level of the roof of the mosque. This indicates that the minarets were already standing when the walls were made higher in 1335. The heightening of the walls also resulted in a row of arched windows that give the building a special character.
In the 1335 renovation, the mosque was heightened, its roof rebuilt and a dome of plastered wood covered with green tiles was added over the maqsura (prayer niche). For centuries the Qala'un Mosque was considered the most glamorous mosque in Cairo until the dome over the prayer niche collapsed in the sixteenth century and the high marble dado was carried off to Istanbul by the Ottoman conqueror Sultan Selim I. The present dome is modern, carried by granite columns taken from ancient Egyptian temples.