This is the northernmost surviving part of the enormous religious complex founded by Sultan Qaitbey, who turned the area into a “royal suburb” with the mosque/madrasa at its centre.
The rab‘ is one of the few surviving examples in Cairo of a once popular type of communal residential building comprising residential units that were rented out much like in a modern tenement house. Each apartment had its own staircase and bathroom (Sufi convents were often built following the same arrangements). The rab‘ of Sultan Qaitbay consisted of no less than 33 such units, very ingeniously designed and placed on either side of the entrance gate. Its façade is 85 meters long, and is entirely of stone, while other parts of the structure are of brick and stone. Although the façade is plain, the entrance porch is ornately decorated. The gate led to a passage at the back from which individual units were accessed. Another gate at the far end of the façade to the north (now almost completely buried by the rising ground level) led to a public street where a sabil offered free drinking water to passers-by. The façade and some other parts of the structure have been conserved, but the building is inaccessible, unused and ruined. The rab‘ was used to house travellers, whose payments financed the upkeep of the mosque at the centre of the complex and its associated charities. Almost every religious building in Cairo was supported by such endowments held by a charitable trust, known as waqf.