Located in Cairo, it is arguably the oldest mosque of the city surviving in its original form, and again the largest mosque in terms of land area. Ahmad ibn ??l?n, the Abbassid governor of Egypt from 868–884 commissioned the mosque. The mosque was constructed on a small hill called Gebel Yashkur meaning "The Hill of Thanksgiving." The original mosque had its ablution fountain in the area between the inner and outer walls. Sultan Laj?n added a distinctive fountain with a high drum dome added in the central courtyard at the end of the thirteenth century.