The qibla wall, the only extant part remaining of the Mausoleum of Umm Kulthum, dates back to the rebuilding (or restoration) by the Fatimid vizier Ma'mun al-Bata'ihi in 1122. This wall displays three widely spaced mihrabs; the shell hood and recess of the central one has elaborate stucco decoration previously absent in Egypt. Flutes, alternately round and triangular in section, radiate from a spirally fluted boss to make up the semi-domical hood, which is surrounded by an outer scalloped edge. The recess of the mihrab is decorated with interlaced bands which intersect at right angles to form stars. The stars in both examples display an outline akin to that formed by placing two squares of equal size on top of each other and then rotating one of them through a 45° angle. Inside each of these stars on the mihrab of Umm Kulthum is either the name of "Muhammad" or the words "and 'Ali."
The mausoleum was probably composed of a square domed chamber, surrounded on its qibla and the two lateral sides by an ambulatory.
Creswell, K.A.C. The Muslim Architecture of Egypt. Oxford: Clarendon Press, Hacker Art Books, New York, 1978.