Egypt: View of the Mosque of Ahmad ibn Tulun, Cairo, Pascal Coste, c.1839

The Mosque of Ahmad Ibn Tulun is located in Cairo, Egypt. It is arguably the oldest mosque in the city surviving in its original form, and is the largest mosque in Cairo in terms of land area.There is significant controversy over the date of construction of the minaret, which features a helical outer staircase similar to that of the famous minaret in Samarra. Legend has it that ibn o¢o«lo«n himself was accidentally responsible for the design of the structure: supposedly while sitting with his officials, he absentmindedly wound a piece of parchment around his finger. When someone asked him what he was doing, he responded, embarrassed, that he was designing a minaret.