Nizam al-Din Ishaq, from Isfahan, was in charge of Sultan al-Nasir Muhammad's khanqah in Siryaqus, twenty kilometers north of Cairo. His own ruined khanqah-mosque sits high on a spur of the Muqattam Hills below the citadel. Remains of some of the Sufi cells are still visible, tiny vaulted chambers each with an individual mihrab. The surviving portal has an eroded inscription, and a fine piece of pharaonic spolia used as a lintel over the doorway. The plan of the building is rather enigmatic and susceptible to various interpretations, particularly since it appears that the structure was heavily remodeled for military purposes at some point. Today it gives the appearance of a ruined castle atop the hill.