One of the most important Islamic monuments in Egypt, Ahmad Ibn Tulun Mosque has some unique architectural and ornamental features. It has been built on an area of six and a half feddans, which makes it the largest mosque in Egypt. It also has additional extensions or ziyadahs to the West, North and South, similar to those in the Mosque of Samarra', with the purpose of protecting and isolating the Mosque from the outside noise. The extensions are sometimes used when the congregation is larger than the mosque's capacity. Piers in this mosque were used instead of columns, joined by pointed arches. The upper parts of the walls contain a large number of stucco windows each having different decorations and geometric forms. It has several entrances and still keeps six mihrabs. The most distinct feature of this Mosque is its old minaret with its spiral external stone staircase, identical to the minaret of the mosques of Samarra'. No wonder, for Ahmad Ibn Tulun grew up in Samarra' during the Abbasid period and when he declared Egypt an independent state in 245 Hegira, he copied the Iraqi decorations and styles of Samarra' in the construction of his own mosque.